Hi k4ts
Thank you for your post. I'd like to extend you a warm welcome to the Community Forum. I hope you find it a valuable resource.
I would suggest to locate the transactions first. Go to Find transactions and search for the payment transaction. After locating the transaction you can now record the refund.
These help articles have the instructions on how to do this:
Please feel free to post again I'm happy to assist.
If my response has answered your enquiry please click "Accept as Solution" to assist other users find this information.
Cheers,
Princess