Hi ars_2001india,
If the buyer has not paid to you, I will suggest you file for
Unpaid Item dispute, to ensure that eBay does not charge you fees on the same.
Next step should be to relist the product, while ensuring that you use
Block Buyers functionality.
The following link will give you more details:
http://forums.ebay.in/thread.jspa?messageID=600001490
I hope this helps!
Regards,
Sapana