Popular Maruti — swift zdi insurance

Address:

Ernakulam, Kerala

I have a swift zdi (Kl41 k 9964) owned on 2016, with maruti insurance.
This time the popular staff named "rajitha" was keep on disturbing me to renew the policy one month prior to my expiry date, as i was being offered a "free service coupon with 6 month validity", which will be served along with insurance certificate.
I have contacted them when i was not received it even after one week.
Then i was informed that "it has been send via registered post"
But it wasn't. To confirm that i asked them tracking number.. But they are not willing to give any such details.
The very next day they told me that "it will be given by hand", again made me fool.
Another day i have called them 47 times, she was not only answering but disconnecting the phone also.
Literally i would say that i was being fooled by the lady staff "rajitha"
So far i didn't receive certificate as well as the offered coupon. What should i do??