Advice please re refunds to a buyer when private seller

[Sunflower6]

I sold two pairs of schools trousers on eBay which were most definitely slim fit buyer has asked for a refund saying item not as described because the hem width at bottom of trousers leg is wider than their sons next slim fit school trousers so they say they are not slim fit! I am now having to refund in full and pay their return postage this seems really unfair.
The trousers I sold are not next trousers!

Any advice?

Although I feel your frustration all you can do is suck it up, and move on.

Unfortunately there is no point fighting this, as you will most likely lose and end up with a defect.

Refund upon return and then add the buyer to your blocked bidders list.