CreditCard Fraudulent transaction case


I am holding Citibank Credit Card, one day on 26th Feb suddenly I received SMS OTP for Transaction of Rs 11650, And in next few moments I received the confirmation of transaction through my CreditCard, which i was having with me and not performing any kind of transaction.
I immidiately informed to my Citibank Customer Care about fraud Transaction and the asked me to block the card, which i requested them to block immidiately , and they asked me to get Police Complaint for this which I have filed with Local Police Station after 1 week, as Cyber Thane was accepting that case because of 1 week passed, so i submitted Police Complaint Copy to Citibank.

After one month Citibank Sent me credit card statement claiming that I have to pay for fraudulent transaction, I have asked CitiBank Customer Care via Phone/Mail but they are saying its OTP Based transaction so you have to pay and they can not stop vendors payment. Now they are adding interest on it and their collection dept is calling me regularly to make the payment,

I am not willing to pay its fraudulent transaction and I already informed to Bank within few moments of this incident.
I have searched on Net and found that RBI has made Rule that if Customer Inform to Bank within 3days about any such fraud transaction, than its solely banks responsibility to settle such matters and bear the amounts charged and not to put the charges on customers head.

Please Guide me to solve this matter.
Rohit R