If you received an AVS mismatch, it means that the address provided at checkout did not match the billing address of the cardholder. If you had an error with your billing address, we did NOT charge your card.
An error like this stops the transaction. However, sometimes when a transaction fails, the bank has already received the request for funds. As a result, the bank holds the money for a few business days for security reasons (exactly how long depends on the bank).
It will generally return to your account after two or three business days. You may contact your bank to find out exactly how long the hold will last.