I was out for vacation and someone took over.

He's supposed to pay 3 purchased invoices. Instead of clicking the amount owing and entering it on payment amount, he put the amount to Prepayment amount. That resulted to unpaid purchased invoice and pre-payment (credit)amount on supplier.

Afterwards he realized that the entry he did was wrong but can't correct it so he tried making another entry and paid it the right way.

The problem now is this.  I  can't  delete the pre-payment amount  he entered.

I don't know if what I did was right and will solve all the unwanted entry without messing my journal entry.

Here's what I did. Went to payments journal, enter the company which he pre-paid. click the pre-payment amount and enter it to payment amount section, and posted it. The pre-payments were gone BUT the invoice to be paid is still there, so I went to Payment and reversed the invoice. 

But then upon checking, on the Payment history of that company, the correct payment made by him was ALSO MISSING.....

Need help.. Thanks in advance.