How can I trace a mobile number

[RainbowPrism]

[phone] = keeps texting me and calling from a 'private number' they wont tell me who they are, but its really bugging me now, I have gathered its a Virgin mobile number...but how can i stop them contacting me, they are getting abusive...my service provider cant block the number either and im getting fed up with it now.

[cherrychapstick]

bigfellah that would be an idea but you can't sent withheld texts

[4getmenot]

just ignore each txt and hang up every call or send them back their own msg.