HDFC Bank Ergo General Insurance — Without my consent make a insurance policy

Address:

620014

Hi,
I am mohan raj,
On 10th jan 2017, a customer care executive from hdfc ergo called me n told about hdfc ergo health insurance,
I told i am not interested, he told abt the policy, i asked him is that mandatory, he replied "its ur new credit card so u can (Must) take it", i asked him twice or thrice, he replied the same, i thought it was mandatory n told ok,

But later i came to know its not mandatory, so i called [protected] requested for cancellation of the policy, they told ur request for cancellation is taken,

So called [protected] n told to cancel, they told ur request is taken, n i received a call from some number +9122* but was busy wid my work so couldn't pick the call, i tried to call that number but some auto generated voice n call got disconnected,

I called [protected] n they told i was not reachable, i re-requested for cancellation, same thing repeated,
Now i need to know, why they need to call me?