Promised $500 reward on a new phone but never received it

I recently switched to xfinity mobile and it’s been a nightmare. I have been lied to every step of the way and I regret switching to this company. During my initial order I was told I qualified for a $500 reward off of a new iPhone 15 plus. I accessed my rewards page and gave them the promo code. Due to agent error, I did not receive that reward. When I notified them of the mistake they opened a ticket but then denied it still. I have pictures of the reward with the promo code. Then, I was offered a buy one get one free line but that also wasn’t given to me. I had to connect with an agent for that. Supposedly he fixed it but only time will tell since I have been lied to before. They also opened 4 new lines on my account that I did not request nor authorize. All in all, I have spent close to 20 hours on the phone and on chat with agents trying to get them to fix their mistakes. This is the most unethical mobile company I have ever worked with. I am desperately trying to find a way to leave them but I have to pay off the phones before I can do so. If you are thinking of switching to Xfinity mobile, don’t do it! They lie and do not honor their promotions.