RBL Bank — Overcharge of cash advance fee without proper intimation

I am one of the rbl supercard holder and I am utilising it for 2 years. It has the feature of cash withdrawal up to 10000 and they charge minimal cash advance fee of 100 rupees.

But with the latest transaction they have charged me around 1500 rupees for withdrawing 10000 rupees without proper intimation.

Even though I made multiple complaints there is no proper response from bank and they are now asking me to pay 1200 rupees for membership which is a pure steal of customer money in a broad daylight.

It will be very helpful if someone guide me how to tackle it .