RBL bank credit card - Credit card fraudulent transaction of from rbl bank customer care number

Dear Sir,
Yesterday afternoon i received a call form rbl bank register number and they told me to upgrade credit card limit by providing otp. They assured me that they called me from registered number so no fraudulent will happen.
After that the ***** has been debited from my credit card.
I immediately called the customer care number and said the entire icident. They block my card and raised a complaint with a complaint number. After that i made a fir in local police station.
Kindly help sir,
I am not able to pay the money due to some financial problems.