HDFC Bank — Non receipt of 5% discount on using HDFC debit card

My father had seen an ad in the HDFC bank ATM in Sept 2014, which stated that a 5% discount/refund is offered on using the debit card for purchase from Snapdeal and a few other websites.I contacted the HDFC bank in Sept 2014 over the phone and confirmed the 5% refund for using the card. My father purchased a LED Tv and a Stabilizer using the HDFC card in September 2014. But till date, there has been no refund as mentioned by HDFC bank. We contacted the bank via phone and was told it would take 75 to 90 business days. Now it is more than the 4 months and yet there is no refund. We contacted the home branch and we are told to call HDFC bank once again. Please provide the correct information.