How to handle a rebate?

[Mark Phillips]

I am running a US  non-profit organization and I am not sure how to handle a
rebate, or if rebate is the right term. We are a sports organization with
different teams. Parents pay an amount as a donation twice a year to cover
the cost of uniforms, tournament fees, equipment, etc.

I have an odd situation this season in that, due to an error at our jersey
vendor, some of the players from last season did not receive a second
uniform jersey, even though the parents paid for it. This season, I am
giving them a reduction in the dues for the cost of that shirt.

I have my checking account and each parent has their own income account, so
I can track how much they have donated (IRS rules). I debit the checking
account the amount of the donation and credit the income account for that
parent. Where do I put this rebate amount? What kind of an account is it? I
guess I could just put it in the memo field of the transaction and use the
net amount for the donation since it is a one time event. I want to keep
track of this rebate, because in a month or two I will have no idea why some
parents paid less than others....;-)

Thanks!

Mark