HELP! STILL NIOT RESOLVE! 830$ device trade in credit with premium unlimited elite upgrade.

Spoke with somebody at corporate escalation two days ago  he said t that my account was still showing my original IMEI number. But that phone was traded in as part ion a warranty claim in December. He said that he would have to take that IMEI number out of the system and put my current devices IMEI number in. And that would take 24 hours for the system to update with the new IMEI number. I did not hear back within 24 hours. I contacted the department myself with the ticket number he  gave me. She confirmed that the original device IMEI number was replaced with my current devices IMEI number. And it would be Refreshed in the system by 7 AM today. It's almost 10 AM eastern and I still haven't heard anything from them. All of this was just for them to be able to initiate the trade-in. The first corporate  escalation guy that spoke with said that he would have to credit my account an additional $400 on top the device trade-in credit  I really need this resolved. It's very frustrating and no fault of mine. I traded the original iPhone in in December as a warranty replacement through Apple. After  Apple diagnosed the phones  as  defective. Aople sent me a replacement phiobne and I sent the defective phone back immediately. Apple confirmed  they received it. Xfinity didn't  swap the IMEI numbers in my account. HELP

                                                                                                                     MY  ORIGINAL MESSAGE TO THE COMMUNITY FORUM

customer service cancelled my order with my 830$ device trade in credit with premium unlimited elite upgrade.

My Xfinity Mobile account says I'm eligible for 830$ device credit if I trade in my current iPhone with my premium unlimited elite upgrade.  I went through all the necessary steps to complete my order online. But when I go to check out it's only offering me a 400$ credit.   I contacted costumer service multiple times. At first they tell me I do qualify for the 830$ credit. I go through the entire ordering process again with them just to be told they can only give me a $400 credit. I have done this 4 different times with customer chat as well as over the phone. On November 8th I tried again. I contacted customer service through chat. she gave me the same story. Im eligible for the 830$ credit. once again we go through the entire ordering process again. Just to be told at the end it would only be $400 credit. She tells me she will speak with her supervisor to see what she can do. After some time she tells me her supervisor was able to get the $830 credit for my trade in.  She sends me the order link for me to approve. The first link crashed. she had to redo the order a second time. finally I got the order link to work. I approved the charges and the changes. The next day I received an email that the order had been cancelled. I really frustrated at this point! I have the cancelled order number and a copy of the order in my Xfinity Mobile account. Someone please help!