Pizza Hut — prepaid cards

Address:

New Delhi, Delhi

i had received 3 prepaid cards worth Rs. 500 each from Pizza hut. But when i went for redeeming the coupon at Pizza hut V3S Mall, Laxmi Nagar New Delhi, Pizza hut cashier old me to message the coupon codes separately to 57575500. I have been charged 100 Rs. for that message by my service provider. Nothing about extra charge for the sms was mentioned on the card. This is not acceptable. Why do i have to pay extra 100 rs. to redeem the cards which are equivalent to cash. i want the extra charge to be reverted back to my account.