A friend recently lost her mobile fone and has the sim card stopped she never kept a note of the number that can block the fone and her network provider has said there's no way they can trace the fone or even tell if it's being used with another sim card, but I've heard on the news before when someone's gone missing the fone was traced! can a fone be traced or is it as my friend suspects that because she was only PAYG the providers not bothered
If a phone is switched on it can be identified by its internal number (which you don't know) or by the SIM (which has been blocked - and in any case was probably discarded). So no, there is no way of tracing the phone.
To locate a missing person presumably they used their phone number - which is effectively the SIM.