i have two accounts on at&t with Reg_bu_081 error

i don't remember i mad two account, but i have two accounts, at&t and prepaid at&t.

it is so weird because when i sign-in on prepaid at&t, i can see my payments and account history.

however, when i sign in regular at&t account. i cannot see my account history. they just request me to combine IDs.

Both accounts use the same ID and password, but show completely different results.

I can't delete one of the two, and I try to merge it, but I get an error called reg_bu_081.

please check this terrible problem.

If the problem is not solved, I will move to another telecommunication company.