Collects money but does not have a clue what for!

Call Center that are useless and cannot provide basic information. This call center does not know what they are doing. They are requested to send account closure statement and Acknowledgement of debt and they tell me to phone the bank as they only liaise for the banks money. How do you collect fees for a bank and not know what it is for. They are continuously dropping the call in your ear and they cannot furnish any proof of your debt.