Thanks for your post and welcome to the community.
I'm sorry there has been some confusion over a credit on your account.
If the credit was applied to the account after the bill was generated, then you wouldn't see an update to your bill as it was already generated, and won't update after that point. It doesn't mean that the credit hasn't been applied. Does that make sense?
I'm not sure what you mean about a credit meaning you have paid more than you should? Could you please elaborate on that so I know how best to help?