EBay member who had bid on my items but never reply to my message

[Bahar]

There are a lot of eBay who had bid on my items but never reply my message after winning the auction. i have tried to contact them so many may times, but they never reply my message. I have left negative feedback to them after contacting them for so many times.
But there is one of them who revenge me by leaving a negative feedback to me saying that i never contact him/her.

It really make me so headache. is there anyone who can help me? i don't know how to report to eBay and kick them out from eBay
Thanks