Shopping. Rediff.com — Defective watch not replacing

Address:

Ahmedabad, Gujarat

I had ordered a Watch through Rediff Shopping and found out to be defective.
Sender of this watch was HP Enterprise - Chennai
I have couriered my watch back HP Enterprise for replacement as it was defective.
I have couriered it to below address & it has been received by them on 27 Dec 2010
(Rediff Order no: 6219629)
Smita Kiran
11,South Mada Street,
Triplicane ,
Chennai - 600011
Mobile no. [protected]
Mail ID :- [protected]@gmail.com
Still I have not received any replacement, even they are not replying on my mails and not picking up calls.