Does the fine imposed on a customer because the bank refused to cash his check constitute usury?

It is not permissible for you to take any money except what is owed by the debtor. Any increase in the debt due to delay or effort in collection is not permissible. Rather, you should only take the debt amount written on the check. However, there is no harm in taking something in return for the effort, such as the cost of going to the bank. But stipulating an additional amount for delay is not permissible.