Kotak Mahindra Bank — fraud transaction through my credit card. bank not supported.

Address:	400614
Website:	www.kotak.com

On 4th april 2018, one fraud transaction of rs.11037 done from c/card. Bank claims it was done under otp but i never received any otp and transaction success message on my registered mobile number. Now bank is not cooperating and they are not giving any proof when they sent otp, which number they sent otp? I have stopped paying them but they are claiming interest and penalties for non payment. No one is responding from kotak bank now. Can any one suggest how can i take action against kotak bank.