I had something similar! Sold a big bundle of baby clothes to a member on ebay, most of them were brand new and the rest were in fab condition, I'm obsessive about making sure clothes look perfect, any stains/rips and they get chucked, so I know they were fantastic. There were 40 items, some small like there were 4 hats, then big pramsuits, so quite expensive to post, far more expensive than I'd thought so ended up paying double. I don't think I even made a profit on it after the postage cost. I wrapped them in a Burton bag, then the lady at the post office recommended I double bagged it with a black bag, so I did. Then sent it first class, ASAP. Should add, all the clothes were damn expensive high street stuff, so nowt cheap, and I'd washed dried and ironed them all the day I sent them.
2 days later I get an item not as described case against me, cheeky fucker tried getting me to refund him TWICE the amount he'd paid inc. postage, altogether he paid £13 and demanded I pay him £30! Cheeky sod! He lied saying they were dirty, which when I finally received them back, I saw he was definitely lying, complained about the packaging (hello? I'm not a store, I'm just selling second hand clothing!). End result, he was investigated for trying to get £30 off me by threatening poor feedback. Bet the bloody weirdo didn't even had a kid.