HDFC Bank — unauthorized deduction - one assist mfee

I am a hdfc bank credit card holder. The bank
Has auto debited rs. 1299/- (One assist membership) from my credit card number ending with 7003 without my concern on date:08/09/2017.
After contacting the concerned department of one assist, they said it has been activated from my end, which is not true. And refused to refund the amount. After some argument they agreed to pay only 400. That is how these hdfc and one assist people are harassing customer. Its been only 2-3 days since the activation and these people are blaming me for activating the membership, which they do it themselves without the customer's consent. So kindly resolve the issue, and refund the entire amount.

Oneassist relationship number : 2651923
Name :- avadhesh kumar sharma
Mobile no. :- 730*32
Credit card number ending :- 7003