Disappearing airtime

I have 2 contracts with MTN and a prepaid simcard, I have come to a point where I am completely fed up with MTN, everytime I buy airtime it disappears and i have made sure that i don't have application running in the background. You can't tell me that I lose R12 for just receiving one what's message. This network is the most pathetic ever, everytime you tell yourself that you will give them a last chance you end up regreting it. I'll make sure that I spread the word on all social networks, I will tell the world of the bad service I receive and amazing enough I have asked the people who are using MTN and they are complaining about the same thing!!!