We have that here too. Usually when you sign up your spam calls actually increase because spammers use the list of "banned numbers" as a list of "verified numbers of real humans".

With CallID spoofing its so hard to track down that violators never get enforced.

In India you have the advantage that the caller pays, which means you have a phone system that somewhat securely verifies who the caller is so they can be billed. In the US the receiver pays so there is no system in place to verify who the caller is.