No worries, I just wanted to understand so I could try to offer advice
I know some mail providers purge accounts and keep them unavailable for a period of time before allowing them to be used again, so that could be the case here.
Do you know the username of the neopets account by any chance? Otherwise, to my knowledge, there isn't much else that can be done. You could try submitting a support ticket and trying to recover the account, but you'd need knowledge of the account to be able to do that.
Best of luck, hopefully someone else has ideas!