Vodacom is useless!

I have phoned Vodacom Customer Care twice about a problem I'm experiencing and they still have not resolved it! As soon as my data or airtime runs out I cant recharge it and the app keeps giving me the following error message: "You've run out of airtime or reached your monthly buying limit" I cant buy data or airtime through the app or via the normal cellphone call menu.

Vodacom is the worst service provider in South Africa. I will definitely swop over to another provider as soon as my contract expire!