no service, mobile network disconected

i loaded airtime and never used it, the next morning i just made a call and the airtime was finished. i called mtn customer service 135, and the person i spoke to said that there is a subscription on my phone and thats where my airtime went to. i told him i never subscribed to anything, i then requested the details of the subscription, he said there is nothing, all he can see is 083 then ***x. i asked him now how will i find out because only mtn can tell what is going on in my account. he was saying a lot of things and finally i told him if i cannot get details, i will report mtn. i got off the phone, my phone all along was properly working. the next thing it says no service. since wednesday night, i dont have network, i cant access my whatsup email nor use my tablet. thursday am i called mtn, the person said they will reset network on their side. my phone still says no service, but the starterpack is workking on another phone. but my mobile network, as per the status of my tablet, says mobile network is disconected. i called in today to mtn to ask what might be the cause and the lady said they only deal with starterpacks and not phones. i just suspected the guy i said i will report mtn to, he is the one responsible with messing up with my network settings.