Missing airtime

2 weeks backs on a Saturday I loaded R12 airtime, at the time I head about 1mb of data left on my phone, I than purchased data for 5mb for R4 of which I was than left with R6 and some cents airtime, I received 2mb for free from mtn which makes it 7mb data on my phone. on a sunday my airtime was gone when I called mtn I was told it was used for internet services than I asked how is that possible when I heard data on y phone. A query *** was logged by an mtn agent and she told me it will take 7 days to resolve the query, I called mtn again on Tuesday and I was told someone will call me back with feedback at the end of the day of which no one called. Today I called mtn again and I have been told queries takes 21 days to resolve. I need my airtime back and I am tired of mtn poor bad service