Cyber Crime Cell, Navi Mumbai — citi bank credit card fraud

Hello,

On 6th oct 2018, i received the call from number [protected] saying it is call from bank and they had all my details such as card number and even cvv which made me believe that it is really call from bank. They told me my redeem points will get expired if i will not convert that into cash or into voucher for which they need otp that comes on my registered mobile number. I shared with the belief that it is from bank because otp received was the same number which i was receiving through valid transactions. As executive told me to wait police complaint i waited. Bank called me on 10th oct to ask for police complain\ cyber crime complain copy so immediately i visited thane cyber crime branch as that was near for me they asked me to visit navi mumbai branch. I have some medical emergency at my home due to which i could not able to approach you before and could not approach you personally.

Please kindly help me with this.
The transaction they have done is 19950 inr which is definitely huge amount for me right now.