My dear Mr Mukherji,
I feel sad.But a few things are just not automatic in eBay.Though somethings are.
1.If the user is registered for less than 90 days,the feed back left by the user is removed automatically in such cases.I lost 2 or 3 positive FBs that way.
2.Since that user is no longer registered,you cant go for mfw.
3.The only option for you is to go to help and write to CS.
I think you will get right justice there.You choose your topic as feedback at help.
Wish you best.
Thanx,
Truly,
Amitava