Calvin Klein - not allowing shopping coupon

i went to b more and compnay, ghaud daud road , authorise retailer of calvin klein ,surat, they insist to purchase more then my requirement to obtain shoppimg coupon in calvin klein , i did the same , they didn,t told me that there is time limit to ancash that coupon neither verblly nor on coupon they provided, i went after **th december**** to shop on that coupon but they refused by saying that the couon is not valid now, after further discussion they said they will send this case to calvin klein for approval . after one month i again went to claim that but they refused again by saying that calvin klein didnt approved the same , so i feeling cheated noe , request to take my complain and let me claim my shopping coupon