Why does ebay protect sellers more than buyers?

i recently bought a scratchplate from 'watchingthewaters' from ebay (uk). it arrived but the holes didn't meet up on my guitar, i wanted a refund, but he told me to 'drill new holes in my guitar' instead. I told him i didnt want to, and after a week of haggling he finally agreed to a refund, i sent the item back but surprise surprise, he said it didnt arrive and that it must have been 'lost'. So i left him bad feedback and he responded with leaving me bad feedback (unjustifiably) then he even reported me and i still have no refund, i hate ebay, other times i buy something and it just never arrives. how can i get my money back?