can not buy airtime via app

I want to buy airtime from my cellphone via my nedbank app!<br> I can purchase a data bundle from my cellphone but not airtime<br> Phoned vodacom 9 times and consultants all gave me different solutions<br> Off course Nedbank was to blame - I phoned them 4 times and they gave different solutions and they blamed vodacom.<br> I still can't purchase airtime. I think these useless people are all ********s because when they put you in this powerless position you blood pressure rises and you might go into cardiac arrest.