Trade in issues

I am in with the majority, I called xfinity rep before I sent my phone in asking if I can take it to the store and give it to them instead of send it in. The rep on the phone said absolutely I’ll even mark it on your account so they know when you come in what you’re doing and everything will be great. I wanted to do this because I was afraid of like every other person. If you read on this for having issues, it would’ve been done at the store and they would’ve had a record of it. So I went to the store after talking with the rep on the phone saying I can and at the store they told me no you have to send it in because that’s how you started everything so we can’t do it. I was at the store for half hour, waiting to talk to somebody and then had to leave and send it out anyways. So I packaged it up very well. Took pictures of what the phone looks like took picture of how I packaged it and sent it through the United United States post office, as that my prepaid shipping label had on it. It only took a few days for the post office to deliver it to York PA. It says it was received by 245 on Monday the 25th and as of now 10 days later, there’s still no record of them getting it. Now I’m being billed for another month of full price when they have received the phone already so I called the rep again asked about what was going on and they have no record of it going in there saying I have to ship it. I told him I shipped it. I told him it was received. They don’t have a tracking number. I gave them the tracking number. They said it only gets shipped through FedEx, but it wasn’t it. It was a post office  I gave them the post office tracking number and basically just got the runaround again saying oh you just have to wait. This is the whole reason why I wanted to take it to the store so I didn’t have to worry about this now two months of paying full price when it was only supposed to be $$11 I’m now paying over $60 for a phone that I returned and did everything that was asked of me. Every time I talk to a rep I just get the runaround I can’t get an answer. I can’t talk to a supervisor. I don’t understand the poor poor customer service. As you are reading this, I would recommend if you want to send a phone number for trade-in maybe try to go to Store or maybe go to one of the other reputable companies that’ll take care of you and at least have good service. You may pay a little more, but you don’t have to keep on paying for something that was promised to you.