i recently got an Telkom Mobile contract sim and cellphone. i ported from Vodacom Prepaid , so i kept my number. I see now that i roam on the MTN network most of the time. i got an prepaid telkom mobile sim and it works fine. so it cant be network coverage. when i do a network search, sometimes i dont see it on the list. is there an setting i can change ?? maybe its sim ?? 