Have money but cannot make calls

It says 17:15. I have R 112.06 airtime, 0 SMS and 0 MB of data. I am trying to make calls but is says I do not have sufficient funds. How is this possible when I still have R112.06 available.<br> I need airtime to get into my complex and now I sit with this problem. Is the MTN system misreading the difference between airtime and data perhaps?<br> <br> Why is it that on a Pay as you go my data gets deleted by MTN when I have not used it in a month???? This is a PAY AS YOU GO service and must be read as such????<br> <br> I need an urgent response please.