Payment recorded against purchase order.

Hi, another employee recorded a payment against a purchase order. This recorded the payment into customer deposits. They then converted the purchase order to a bill and then recorded payment via the electronic clearing account.

The problem I have now is I cannot reverse either payment to correct the issue and I still have a payment in the electronic payment window waiting to be processed. It will let me reverse the original Invoice to create a refund, however I cannot apply it to the electronic payment to reverse.

What can I do?