Trade ins not credited

I’m so frustrated with Xfinity! I traded in 3 phones back in December. All 3 were accepted but only 2 got credited. After multiple phone calls and promises they would resolve it promptly with now results. I just called today and was told it is ineligible because it was damaged. I told them in no way could it be damaged. It was accepted and i had sent it back in its original box then bubble wrapped and put in another box. Then in February i traded in my daughter’s phone with the label Xfinity gave me and was told mis matched serial number. I went to Xfinity store and they made a phone call and gave me a new label and i sent it back out. I got an email saying it was resolved but still no credit applied. Now they are telling me they sent it back to me, which no, they didn't. So now Im out 2 phones and no credit. I feel like I was scammed! Both phones were in excellent condition and I wouldn’t have traded them in if I knew this was going to happen. I was promised trade in value for all 4 phones, thats why I switched to xfinity for mobile. I have tv, internet, and phone with comcast an am a diamond customer. A lot that did for me! So disappointed but can’t leave because 2 phones were credited so now i have to wait 2 years or id be out double the money. Is this trade in deal a scam?? Sure feels like one!