I'm pulling my hair out and no article seems to actually provide the steps to do this, although the QBO help says you can (they just don't walk me through the steps.)

A customer paid $800 for a service using an invoice I sent them. Then, there was a problem and I offered a $200 refund. I already know I can't void the transaction, I need to refund to their card. In following the apparent process, I went back to their original invoice and reduced the service cost to $600. Now the payment receipt is showing a $200 credit.

I went to select Refund. and it appears it will refund the full $800 - I do not want to do this. How do I refund $200 back to their card?

Thank you in advance for help!