Harassment by Bank

Hi, a few transactions of my RBL Bank Credit Card were converted into EMIs and I never called them and gave any consent to them for preclosing the EMIs; but they did so without my approval and sent me a Statement with complete preclosure amount. I've escalated this to them several times and let them know that I did not call and according to them they were supposed to do a verification call also with me before preclosing the EMIs, which, they did not and they agree that they did not! Now, I've been requesting them to reinstate the EMIs and send me the revised statement but they aren't doing so and I requested them to produce the proof that they received the call from my registered mobile number for preclosing request, they aren't paying any heed to this. They have been behaving absolutely irresponsibly since the time I've escalated this issue and just 3 days back k they have again sent a mail to me lying saying their call record shows I've given them the consent to preclose the EMIs. I did not do so and they are being deceptive here and lying. Can you please help?