[Resolved]  Big Bazaar / Futurebazaar / Future Retail / Hometown — not received monthly kamai offer 300 rupees cashback

I am rohini from pune.
I shopped for rs. 3050 inr on 6/08/2017 big bazaar said cash back money will be added to future pay wallet in 10 days. But i didn't received cash back. After 10 days i called future pay and i came to know that big bazaar made mistake will entering my contact number. My last digit of mobile number was wrongly entered, so the future pay customer service said they registered my complaint and correct my number and said now money will be added in your wallet in 4-5 days, but i didn't received cash back, again i called, this time they said our system is down call later. Again i called future pay but it was continuously coming busy so i called big bazaar they said you will not get cash back. Your registration is done on 27th august which is not valid now.
I think future group is not taking customer complaints seriously. Customer only have to follow up and call them again and again to remind.
I want explanation from them why they did this. Their is no value for time i have spent calling them again again.