Snapdeal — I have still not received my refund amount

My name is Sangmu Lepcha ... I had requested for a refund amount in Snapdeal and it said it's on process since September 11 and still I haven't received my amount... I had ordered the item through cash on delivery now they are asking me to provide the bank details in PDF format which is really complicated ...I tried to contact them but m not receiving any satisfactory replies .. I even asked for the customer care representative number so that I could talk to them but they are not providing me with the number... If any one could give me the number please give me so that I can talk to them directly