I'm sorry but [I'm old!] I am not following this. Is this a refund that you have sent [in cash] to a buyer or a payment [in cash] for something that you have bought.
In either case it would seem a dreadfully risky way to deal with it.
You must buy [and pay] things through the eBay checkout on each sale or by cash when someone picks up an item from you. If you need to refund that is done through the resolution centre.
EVERY SINGLE TIME! [Yes I know - shouty...]
@mor_488409
