This is a terrible non-solution.  QB used to let you create a credit memo for an over-payment. Your work-arounds are all very unprofessional.  Telling my customer to apply any number they want to the credit is asinine.  The choice should be to refund or create a credit memo, simple as that.  My customers require credit memos with reference numbers and I can't provide that with QB Premier Desktop.  Please put this in the next update.  It is a serious flaw.