HDFC Bank — False and wrong commitment from HDFC

Be very aware of any product from HDFC. HDFC bank officials are corrupted and if you make any complaint against them, they never take any actions at all. However, I had a small relationship with ICICI bank and there also I faced some problems with their staff, but when I raised concern for those officials, ICICI really helped me a lot and addressed that.
But the experience with HDFC is nightmare. Let me tell you in details:

I have my salary account and credit card with HDFC (unfortunately). I received call from HDFC's regional head office, Kolkata and they try to sell me a product of HDFC life. After several minutes of conversation they convinced me to buy a HDFC life product (another mistake of mine). I only convinced as they told that they will convert the purchase on my HDFC credit card into Dial an EMI (DAE) with 0% interest rate. They also informed that there will not be any fee for the DAE.

But they have provided totally false commitment. The purchase amount had been converted to DAE but I had been charged. I had called several times to them and every time they replied it will be reversed - which never happens.
Next concern - the big one. They informed next year onwards the premium amount will be automatically converted into DAE with 0% interest rate, as happen at the first time with no extra cost. But it does not even converted into DAE and a huge amount of credit card bill has been generated.
I have raised several concern with both HDFC bank and HDFC Life though nothing has been resolved.

Even HDFC bank is not answering the simple question of - if at the 1st time the amount was converted to DAE - I had not called to customer support for the DAE, I have not done anything; then why it is not getting converted to DAE this year?

Several times I have provided the details of HDFC officials who were involved, but they have not took any action. I am providing here the details again:
Name of the caller is - PRATIMA, she called me from HDFC credit card regional office, Kolkata. She is available in the no :[protected]

I had discussion with my financial advisor of my HDFC life as well - AMITAVA KAR CHOWDHURY, Kolkata Branch Office, Kolkata - 700001, ML CODE ONE, Mob - [protected]