Airtime Disappearing/ Theft

I have e-mailed and called MTN. As you know the chances of getting through to someone and that same person sorting the problem out are slim to none. I have noticed recently that i have data and airtime loaded on my phone. I make no calls or sms's but my airtime seems to disappear? I suspect MTN are charging my airtime instead of data. Quite a clever money making scheme as it makes one buy a lot more airtime because without airtime we cannot use data. To summarize i would really much appreciate if MTN can stop *****ing my airtime, I have checked and i have zero Wasp services as well so the only conclusion that i can come up with is the MTN has resorted to theft to increase profits knowing full well that the customer service is not equipped to sort out any such problems. I am definitely moving away from MTN. In the short run i'm sure MTN will make a lot of profit but in the long run people will eventually find out that MTN is *****ing airtime and leave. To resolve the problem, kindly pay back my airtime...and i bet i have 2 chances of that happening... Zero and F-all.