Star Health And Allied Insurance — spam marketing calls from star health insurance

Address: Chennai, Tamil Nadu

Of late, i have been receiving lot of annoying spam calls from m/s. Star health and allied insurance. These irritating calls not only consume my time, but also cause rs.70 per each incoming call as i am on international roaming with vodafone. I attended 3 of 11 such calls today (Alas! True caller app shows the caller id only when the call is over or missed and not during the active call). I am desperate now to find a way to stop this menace. Kindly guide me.
Thanks, baskaran.