Big Bazaar / Futurebazaar / Future Retail / Hometown — Arbitrary Change in Terms and Conditions

Address:

Kolkata 700075

After payment of 10000 at a time to join profit club membership, the terms of which was to credit ₹1000 every month in my account for purchases. But this month, on 1st Sept, although ₹1000 has been credited in my account but my balance is showing, ₹750. How is this possible, when I have not purchased any item this month.
Even after my complaint three days before, nobody is interested to resolve the issue, best known to the management. Really frustrating in some situations.
Although, having the complaint resolution section, no step has been taken by the management team until the same has been published in Twitter. It also absurd, that after accepting consumer's money, they feel it privileged to set up their own terms without any knowledge or consent of the member.