Full or partial refund

Sold a skirt for $51.  Buyer has emailed me in regards to a damaged zipper that will cost $25+ to repair.

 

I checked the zipper on numerous occasions and found no problems whatsoever.   But the buyer is adamant.

 

If I thought there was a chance of the zipper being damaged I would immediately cough up the partial refund for repairs. But I'm not convinced. I immediately offered a full refund on the return of the item but buyer seems happy to have repairs done.

 

Where does this end?  What happens if the skirt is damaged / greatly altered by the repair process?

 

I felt a full refund was the safest route to travel.

 

Buyer has had a couple of partial refunds recently due to repairs.

 

Many thanks .....!