The complaint also alleges that Citizens Bank directly violates the terms of its account agreement by allowing purchases and withdrawals even when a customer has an insufficient balance . � � For example , one contractual provision states that the bank will not allow withdrawals when there are insufficient funds . � � In fact , the class action alleges that the bank does allow withdrawals on insufficient funds even at its own ATMs -- and it does so without any prior warning to the customer . � � According to the complaint , the bank does this for the sole purpose of charging its own customers an overdraft charge .