Negative feedbacks from fraud buyer !!!

[t.2020]

I have been registered and selling on ebay from the past 3 years.
We have only two negative feedbacks in our account and that is also left from a FRAUD AND GREEDY BUYER.
I have got only 2 negative feedbacks from same buyer holding two ebay account and both having the same pincode and city and purchased same handset after 10 days.
After getting the handset buyer said he will leave two negative feedbacks if we will not give free memory cards which was neither mentioned on the description nor we never promised him , he raised ebay guarantee claim that was also rejected. When we approached for removal of feedback he again left the second negative feedback with negative follow-up comments.
We sold the same handset about 30 pieces to other customers all with positive feedbacks and no problem or anything, But this buyer has mislead all my customers with his false comment and has also tried to fool us and ebay.
We have marked ebay several mails regarding the same but ebay is not listening at all, we tried with phone calls and emails also but the buyer is very greedy and he is still saying he wants two 8 gb memory cards !!!
Please help ebay members if this types of buyer will be here on ebay then there will be not a single genuine sellers left, every seller will have to think about other alternatives then !!!

[paylessindia]

Iam a new seller.
I got the the message ,item sold and shipped out the item same day DTDC. I confirmed the shipment details in ebay page and also sent scanned copy of the AWB copy and later screen shot of Courier web site tracking page directly to the customer mail mentioned by ebay.
say after the item get delivered in 2 days, courier web site tracking page screen shot showing item delivered is enough as POD or should I get a seperate electronic message or paper proof from DTDC?
Iam sure customer will confirm receipt inside the paisa pay system.But can I be proactive and provide proof as item delivered already?