Upgrade keeps getting cancelled

I tried to upgrade one of our lines and it got cancelled because they couldn't verify it was me making the upgrade. I was instructed in the email to go to a store. The store said they couldn't do anything so I had to contact customer service and have the upgrade reversed. After an hour with customer service they finally reversed the upgrade and assured me I could upgrade again without it being cancelled.

I upgraded again and now a day later it's been cancelled. Where do I even go from here? Why would someone log into my att account, upgrade my phone for me, have it sent to my house, pay with my credit card, and somehow have the code that was sent to my phone for verification? 

Really annoyed with this. If I have to spend another hour on the phone it'll be to cancel my service. Hopefully someone is willing to help.

Mark