MTN *****ing airtime

Since yesterday my airtime balance has dropped over R100 but my data has not decreased. I therefore have lost over R100 in airtime through mobile data usage when I still have a little over 400mbs left from my last bundle. What has happened to my airtime? Where has it gone? Why spend money on a data bundle if it doesn't matter?<br> My opinion is that MTN is *****ing my airtime. I expect the airtime which I have lost through data usage to be returned to me asap. I have already started informing everyone I know of how MTN *****s and to not consider them especially when they just up contracts fees. My contract fees are going up, but I am getting far less. I will take this to the ombudsman should this matter not be rectified.