Respected Sir/Ma'M

I am kuldeep Singh. I purchased one badminton Racquet by PlayGroundOnline on 29th Nov. 2011. I placed order (order number 146805) through my friends account for Yonex Nanospeed 850 Badminton Racquet. But playground online delivered me Yonex Nanospeed 500 racquet. Just after receiving racquet i talked to customer care team of playground online. They said we will refund your excessive money if u prefer to keep Yonex Nanospeed 500. I said it is fine, refund my money back. But till now they have not taken any action in this regard.
Kindly take action against them.

My Contact Address:
Kuldeep Singh
09278461162
Room No. EC-07
IIT Delhi, Hauz Khas
New Delhi
110016