Xfinity lies and does not keep its promise to clients

I have used Xfinity internet for years. Each year I had to call the sales department to get a promotion and continued another annual contract. In Oct 2023, I called again and was offered by an agent (forgot the name) a promotional bundle package of mobile and internet. The agent said that I was eligible for the "buy one get one free" mobile plan for the original price of $30 per line for one year if I transferred two mobile lines over to Xfinity, as well as other discounts applied to the home internet service for two years. On the phone conversation, the agent explained to me how the bill (for both internet and mobile plans) looked like after the application of all the promotions, however, the agent also stated that there would be chance that the promotion might not apply to the mobile plan in the first month but would show up in my account in the second month, and that If the promotion still did not apply in the second month, I needed to contact the billing department to resolve the problem. I thereby viewed this as a business contract, agreed on the terms, and transfer our mobile plan (two lines for me and my wife) from AT&T to Xfinity. Our plan was to at least stick on Xfinity for two years to fulfill our contract. 

As expected, the promotion did not apply to our first bill of the mobile plan on Oct 2023. I was charge for $85.28 ($30 regular charge each line, $10 activation fee for each line, and other miscellaneous fees) for the first month, and had no problem with the charge. In the second month (Nov 2023), the promotion still did not apply and I was charged for $60 plus other miscellaneous fee, so I had to call the Xfinity customer service and explained to them my situation. One of the supervisors (didn't know the name) handled the problem for us, and got our bill down to slightly less than $20 thereafter. To be frank, I did not know how they calculated my Bill to be under $20 and thought that would be part of the promotion. I got the deal for about half a year.

Today, I received an email from Xfinity stating that the bill for next month will be $64.26. I immediately recognized the problem, called the customer service (the billing department) again, and explained to them the situation, as well as what I expected (the "buy one get one free" promotion should apply to my account for one year, not half a year). The first agent (I didn't know the name) took a look at my account and offered to me a potential solution that was pending approval from the supervisor: I should have got award for $30*12=$360 under the promotion and they have applied $45*6=$270 in my account, so the agent would look into the potential solution of manual application of the $90 credit to my future bills for the next six months. Then after talking to the supervisor for minutes (I was on my cellphone line for over one hour as of that time), the agent came back to me and explained the situation: Unfortunately, I was not eligible for the "buy one get one free" promotion for the mobile plan. There was a glitch in the system and that was why $270 was applied in the past six months. They could only apply a one-time courtesy $20 credit into my account. I was not satisficed with the solution and requested to talk to a supervisor. After waiting on the line for another 15 minutes, a supervisor (called [Edited: Personal Information] with a title of Chief Manager in the bill department) picked up my phone. I basically repeated my situation and my expectation that I did not expect any additional credits but just wanted Xfinity to fulfill the promise/contract. However, the supervisor insisted on the proposal the previous agent offered. Specifically, the supervisor said something like "I am sorry for your situation, but the agent did not provide you with the right information. You are not eligible for the "buy one get one free" promotion to your mobile plan since the credit was applied to your home internet plan. So we can not do anything today except for applying a one-time courtesy $20 credit into your account. We will probably file claim towards the agents who gave you the offer". I also asked the second question. Since the cellphone provided by Xfinity (a Samsung phone) has got some technical issue (we can not use the speaker), can we change it to our own iPhone? The supervisor also told me if we did that, we would lose all the promotions applied to our account. Overall, I spent nearly two hours with the customer service but still did not got what I was promised for. Xfinity would rather file claim towards its own agent but not fulfill its promise to clients. Why do I care about whether they file claim towards their agent? So funny!!!!. I only expect to receive what I was promised for, no more no less. We just need to go by the contract. Even oral conversation from an agent represents the promise of a company, right? 

Now we stuck. Basically, we changed our mobile plan to Xfinity but never received what we were promised at the beginning but had to use a broken phone for the next two years. Xfinity only gave you a service contract, not a contract with detailed pricing listed, so they interpret the terms to whatever way they want to. If we want to terminate the contract, we had to pay Xfinity early termination fee. According to my experience above, Xfinity has a terrible corporate culture keeping its promise to the clients. Specifically, one agent can say one thing and the billing department does not fulfill the promise. Additionally, Xfinity only allow you 15 days to test and request a replacement of the cellphone you got from them. After that, you would have a one-year warranty from the manufacturer but that only covers the repair, not the replacement. If you don't have any repair shops within your region, you have to mail your phone over for them to fix. Then you do not have your phone for weeks or even months. Accumulatively, I have called Xfinity customer service over five times in half a year. I used AT&T for close to 20 years in the past and never had to make so many times phone calls to customer service. I would not recommend Xfinity to anybody. This is a terrible experience. I only asked for what I was promised for but never got them.