HDFC Bank — credit card one assist service payment without knowledge

Address: Sirsa, Haryana, 125055

Hi,

I have get a new hdfc credit card. But out my surprise rs. 1299/- charged on my credit card account without any kind confirmation/intimation to me as oneassist membership fees. Now i am struggling with hdfc and one assit customer care to get it deactivated for last 2 weeks for this unwilling membership fees reversal/refund.
I need a help to get this membership deactivated and do a reversal of membership fees.

Without my confirmation oneassist membership fees rs. 1299 has been added in my card. Why this has been added?
I want immediate reversal of this fees.
As confirmed verbally, that this card has no associated hidden charges. Its absolutely free. Till date i did not use this card. And now i am afraid of having some more hidden charges. So i want to surrender this card post reversal of this unknown hidden charges. Please let me know the process thanks.
Rohit