Open unpaid item case and close after 7 days as ebay required.
Contact TNS for malicious bidding activity,feedback extortion and emphasise that buyer just bid on your item to give you negative and blackmailing you for extra shipping discount and he never want to pay you in first place.
Make clear cut case of malicious bidding,blackmailing for special discount and abusive language and mail to trust and safty.
Dont forget to mention buyer's abusive and blackmailing language
Keep the all the mail and send to trust and safety with header when they require
Call to ebay or contact live help and ask about your account manager and discuss case with him/her
http://pages.ebay.in/help/contact_us/_base/result_6_6_3.html?item=&dsturl=http%3A%2F%2Fpages.ebay.in...
Samin