Unprofessional Upgrade

About two weeks ago I upgraded my contract and changed from one package to another and got the Iphone X. Today at around 10:30 I wanted to make an important call and got a message that my talktime limit was reached, which was very strange. I immediately phoned Vodacom customer care and the lady told me that that is just they way it is, she said to me that the consultant should have told me that there will be a day which I would not be able to make calls when the old contract falls away and the new one kicks in but surely that should be at midnight on the last day of the month. I then asked her if I would be able to buy some talktime on my app and she rep**** yes to my answer but I was unsuccessful. I could not make phone calls the whole day and phone calls are part of my business being a medical representative. I am so sad that I signed up for another two years with this unprofessional service provider but this will be my last two years with Vodacom?