Can't delete old account address

Please someone help, I've been on with customer support for 5 hours and they have hung up on me. I guess I have an old account address that is connected to my mobile account, and every time I upgrade a phone, it sends it to the old address instead of my wifi/cable address (new address.) This has been going on for five years, every person I have talked to has assured me it has been resolved, but it has not. The last person I spoke to seems to think that my xfinity mobile account was created first at my old address (5 years ago) and when I moved to my new address, I created a new account - with the same log in information - and the old information is still linked somehow. When I go to my mobile account, I can see that the email address is wrong, but then when I try to go change it, it routes to my main xfinity account and that only has the new address. Please for the love of everything holy, someone help me. I can't keep doing this 5 hours a day to end up shipping my phone to my old address every time we upgrade.

This does nothing and keeps my old email address. Then I click on the xfinity account profile link and it shows the below

And when I try to order the phone, it says my internet service address is an old address - which as you can see above, my current address is my service address.