Customer Overpayment
To preface my issue, I will start by saying we run an accrual based accounting system, whereby our customer invoices are not recorded until delivery of the product. We also use progress payments for our customers to pay by (eg. 20% deposit, 70% on delivery, 10% on completion).
Yesterday, I had a customer send us a payment which was more than they intended to pay (mix-up by the bank teller). The customer had already paid their 10% deposit over a month ago, and they were due to pay the next installment (70% leaving the final 10% to be paid later). However, the bank teller misunderstood and paid the full invoice amount, including the deposit amount which had already been paid.
Now I need to refund the customer the overpayment of the deposit amount plus the final 10% payment which wasn't yet due. However, MYOB won't let me issue a refund without the invoice being recorded as an invoice, and even then, will only allow me to refund the deposit overpayment portion. The customer needs all the excess funds back. How do I get around this?