The program called NoMoRobo (NoMoRobo.com) will stop robotic calls from ringing your phone. It is a free app. It already works with the other major phone carriers but not with T-Mobile. The reason for that is that the phone needs 'simultaneous ringing' to work. If enough people ask T-Mobile to add that service, they would probably do it. Please call them and ask them to add the service. Thanks.
More information: http://finance.yahoo.com/blogs/the-exchange/block-pesky-illegal-robocallers-220537765.html?soc_src=copy
Get-started site: NoMoRobo.com