Bought iPhone at Bestbuy but activated at ATT store, now have two NEXT plans instead of one!

On April 24th Bestbuy had a promo to buy an iPhone X 256 for 999$ which was 150$ off. It was a great deal so I signed up on Bestbuy's site to get the phone and have it added as a new shared account on my plan with ATT. When I tried to activate the phone after I got home it wouldn't activate so my wife and I went to the ATT store to get them to help. The ladies at the store said the number tied to the phone was reserved/locked or something along those lines and they would have to get a new phone number tied to the phone. To do that they said they needed to cancel the NEXT plan that best buy apparently setup and make a new one for the new number. I repeatedly asked if this would result in two NEXT plans on my account for the same iPhone and the Store Sales Assistant Manager said absolutely not and if anything wrong happened she would correct it. Long story short, after 3 hours of waiting I finally walked out of the ATT store with my new iPhone X activated. It took 4 sales reps 3 hours on the phone to do so all the while my wife and baby were waiting in the store with me.

Now come the latest bill and SURPRISE! TWO NEXT accounts on my bill. One for the 999$ price and another one for 1149$. I went back to the ATT store and the same Manager opened an incident and a case for this issue. She said it would be resolved on July 10th and that I would receive a call. I never got a call on the 10th. I emailed the manager, no reply, I texted her at her number no reply. I waited 2 more days and texted her again and she finally replied that she would be in the store on Saturday the 14th. I went to the store to meet her and she gave me an excuse that she was doing administrative things in the back and made another employee help me. 2 hours of waiting at the store and the other lady told me the original case was closed with no resolution so the rep she spoke to on the phone opened a new case with the same incident/case number and that should be resolved today the 16th of July.

I looked in my wireless account and still see the two NEXT plans on there so nothing has been resolved. I need help with this asap as ATT ruined my account. With autopay I am out over 140$ from my last bill because of this extra phone and now it is coming up to being time for another billing cycle. @AttCustomerCare please help me.