American Express Travel Card Credits Issue

Hi,

We are on R12.2.4 using iExpense. American Express travel card is being used as both pay.  we are trying to figureout how to manage credits.

Let's say Employee charged Air fare in Jan-20 for $100.. expensed and company paid Amex $100 in Jan-20, sent amex remittance file.

Later the employee cancelled the airfare jn Feb-20, Amex returned -$100 to his travel card, expensed it. Now when we run payment it short pays $100 to amex since we run payment for amex for all employees. also it sends as positive amount to amex in the remittance file. This is causing issue at amex...showing as debit amount.