I sold a breast pump, complete with all accessories and some extra bits (I had to buy new parts for it while I was using it), some new, some used. Sent item first class and it went missing, then arrived at buyer's address with the outer box I had packed it in missing and one of the 'hygienikits' (set of bits you use to get the milk out of one breast) also missing, as well as a few of the extra bits (buyer sent me photos). The buyer would need to buy one new hygienikit to use the machine - they are £13.50.
Buyer has requested a part refund of the price of two hygienikits, on the basis that I will claim refund from Royal Mail. (Parcel did not have extra insurance as it only sold for £40). This would mean me refunding her £27. (I specified in the listing that the buyer might want to buy new hygienikits anyway as they were all used.)
My partner thinks I should say 'Thanks for the photos, I'll put in the claim and give you a part refund when I get the money'. I'm worried about getting into a fight though! Any thoughts...?