Buyer Wanted to Return, I Sent Label, Now Just Wants Partial Refund, Is This O.K.?

[ricketts62]

My buyer wanted to return an item, I sent a shipping label, they then asked some questions regarding the item and decided they just wanted a partial refund.  eBay now gives that option and i am willing to send a partial refund.

My question;  Since I have already o.k.'d a return and sent a shipping label, is it o.k. to send a partial refund? They are supposed to return by 8/14/2015.  I can see me issuing a partial refund then they they change their mind again, return the item and eBay will check tracking & expect me to issue a full refund when I get the item back.

Any advice?