Spykar — jeans was available at 20% discount but sold to me at marked price

Address:

700107

Today i purchased one jeans pant of spykar brand from shoppers stop at 3799.00 hence 20% discount tag was attached with the jeans but they denied to give the discount saying spykar have no discount now on single piece you have to buy 2 piece of jeans to avail the offer but there was nothing mentioned in the label attached with jeans. I am attaching the pictures also