6ten — Accor Food Coupon billing

Hello,

Recently the 6ten shop in Prafulla Kanan Road, Kolkata, started accepting Accor food coupons. But when I bought items from the shop, I came to know they charge extra amount if paid by coupons, whereas it is not mentioned at all. Also in the bill they never mention the extra amount charged for food coupon. Please take corrective action against these frauds.