The correct answer is that there are no refunds. Credits are non-refundable. Money goes in and doesn’t come back out. Added to terms of use in a sub-page, and a help article about prepaid credits at help.openai.com.
And you certainly won’t get a free grant of $5 paid to you just for signing up. If you got banned and you got a refund of money they gave you to a payment method you put in, sounds like an accounting bug.