I bought a phone on eBay using BIN. It was advertised as New Other but I could tell it was used when it arrived (few scuffs on back, sticker on sim slot peeling, box beat to hell etc. but in excellent condition for used so I can see why he did it). However I was unable to get the phone to work any sim for the network it is (supposed to be?) locked to, even ones that definitely worked in other phones (I think this is related to it being used). I took it to the service provider's local shop and they couldn't get it to work either.
I contacted the seller and had an email exchange about it, and finally arranged a return through email. Should I now organise the return through eBay or rely on the email communication as good enough?