Does anyone know how to not allow blocked,private,unknown callers call your phone and to only allow your contacts to call you?

I think your network provider might be able to do that, but I'm not entirely sure that it's possible

Edit: If you are trying to stop sales calls then you could register with the Telephone Preference Service to opt-out from receiving such calls - http://www.mpsonline.org.uk/tps/

Edited at 01:17 Thu 07/04/11 (BST)

i think if your device is jailbroken, then there is a app on the jailbroken store to stop this, and also blacklist anyone else that you dont want calling you or text messaging you.

-Jack