Reliance Footprint — Enquiry on whether I was scammed or not

I had purchased a product of 5, 700/-, which a skechers shoe. However, I did not like the product and decided to return the product within 7 days. I happened to visit the store on Saturday evening and they asked to buy another products which are worth 5, 700/-.. There was also an offer which was provided by reliance which was "Buy 2, Get 1 Free" Offer. However, after the billing.. they had added the bill amount of the third product as well. Now we had paid extra amount of 180 around. I really need to have a contact with reliance customer care or anyone who have an idea regarding my issue.