Star Bazaar — Cashback did not credit in my wallet

Dear sir,
my registered mobile no. on star bazar is [protected]. currently i am in pune.
i was eligible for Rs 75 cashback offer for all my previous 3 orders. but all the three times it was not credited to my wallet. every time when i complain your executive gives me a rs. 75 coupon. this way i have three coupons worth rs. 75. if every time it was credited to my wallet it would have been accumulated as 225 RS and i would have used amount at once. and in the case of coupon i am not able to use more that one at a time.
today too your executive told me to provide coupon, but i refused. kindily cancel all those coupons and provide me a single coupon worth addition of those three i.e. 225 rs. also after every order i am getting cash back and its not being credited to my wallet. pls make sure this doesnt happen in future.