Kotak Mahindra Bank — Unable to cancel credit card

I fell prey to their credit card marketing hoping I won't receive any calls regarding credit card as promised by the executive. As per the executive Mr. Karthik (mobile.[protected]), he forced me to apply for the credit card promising he would cancel my credit card application so that they won't be disturbing for credit cards via phone calls
After applying for credit card I received the credit card and I am not able to cancel my card and the executive has blocked my number