[Resolved]  HDFC Bank — debit card rewards point

As per the Bank's T&C, for using my Platinum Debit Card for making a payment, I should get certain rewards points based on type of merchant.
Now suddenly I saw that my points were debited from my account and it is showing as negative balance. I complaint against this in my bank's customer care. They lodged the complaint and the resolution they provided is that from 1st May 2017 to 30th September 2017, due to some technical fault, some points have been rewarded by the bank that should not have been rewarded. The points were wrongly credited so they pulled out the points without intimating me.
Upon asking for the details of those transaction that for which transactions Bank has wrongly credited the points, they have shared the details of 72 transactions done via my debit card for which I should not have been credited the points.
Now surprisingly within the mentioned time frame I did only that 72 transactions using my debit card and I checked that I was rightly credited the points at that time. But the bank is not accepting the fact, they simply telling that you were not eligible for the points.
My question is that how is this possible that during the mentioned time frame and out of those 72 transactions all the 72 transactions are not eligible for the points and not a single transaction was eligible?
Second why the bank has given the points at that time then and now after 11 months they came to know about the same?
I want you to look into the case and take action against HDFC bank because I am facing this type of problem many a times