How to stop unwanted commercial call on your land line/mobile phone?

Unwanted commercial calls and sms are always irritate and created problems to the users of phone and mobiles.The phone and mobile users raise their problems on various forum to get ride from these unsolicited calls from telemarketing companies. To stop such unsolicited calls the TRAI  had taken several steps  like creating of Do call /Do not call registry but they did not get success as telemarketing companies take the advantage of loop hole in the TRAI's order. The height of this unsolicited call reach at peak,  when some one from Telemarketing company   made a call to Finance Minister Mr. Pranav Mukherji and started motivating and requesting  him to take home loan from some bank,  where he was  attending  a  very important meeting .