Since January 2019 you keep are sending one of your customers a bill for $72.21 CREDIT. So far your ex-customer spent a fortune on calls to you however the incompetency of issuing refund cheques is beating all the records! Can you calculate how much it costed your company on sending monthly bill for over 4 years with credit balance? Is the a hope that the refund cheque will arrive while the customer is still "around"?