No Seller Protection

I recently tried to sell my phone on this site - I stated the phone needed a new battery and charger in the ad write up and found a buyer. I delivered the phone to him on Saturday (30 May) and upon delivery he turned on the phone, checked it out and was happy with it. On Monday (1 June) he messaged me and told me the port was damaged (the port was not damaged when I sold it) and he demanded a refund. I told him I cannot refund him. I asked bidorbuy for my money and they refused to pay as he was not happy. I asked him for photo or video proof that the phone was not working with new battery and charger and he failed to provide that BUT bidorbuy still insisted, without investigating or showing the slightest ounce of interest in the matter that I send a return address and allow for the refund. I have no problem with the refund my issue is the fact that no one followed up and made sure he did not damage the phone. I also cannot be guaranteed that I will receive the exact same phone back - he told me he destroyed my battery but all of a sudden he still has it? I just wish more care was taken. I am not happy and am done with bidorbuy, they are lazy.