When a withdrawal is sent to a closed bank account, several things could happen.
1) Deposits sent to a closed bank account or canceled debit card may be held by your bank until you contact them. Your bank may also issue a check to the address they have on file for you.
2) If the debit card number you used has changed but the bank account is still active, the funds may be returned to your Nanovest. If they are, you can deposit them by linking a new bank account.