Data depleted instead of airtime yet airtime it's being paid but by bit

MTN is making our life's miserable because of the way their services are being handle I'm really not happy that now I can't purchase data because of the advance taken which I'm well aware of and it's being paid everytime Im being send airtime worse now it's data really their service is not on your loosing customers but by bit I can't purchase data now in the middle of the night or anyday should I have a problem who to contact

Last night had a serious emergency at home I couldn't WhatsApp call my parents for help because MTN decide to take my last data that was send to me

IM REALLY DISAPPOINTED