Hi, I hope to be your guide through these issues, and apparently a few others have been strangely affected by being bumped back down to free-trial limitations or not getting limits lifted instantly even though a payment method was entered.
First, you might need to give a payment and your prepay credit purchase some time to be processed and take effect, even though the balance appears to be added to your account instantly. It is the actual charging of your payment method through the payment processor that seems to be the trigger to transition accounts into the “paid user” status.
Other accounts with no reason not to feed more money into the system had their next credit purchase clear up the problem, but I wouldn’t recommend going right to that without knowing more.
You can let us fellow users on the forum know a bit more about the sequence of events, how long you’ve been a paid user, how long you have waited, if you ever had a payment plan in the system before - and if indeed you’ve actually been charged yet. That will help provide better actions to take, and ultimately someone from OpenAI might skim across the collection of reports. 