False contract information!!!

About two months ago I received a phone call from Vodacom to possibly migrate to a more affordable 'contract-option' as I was overspending on data costs. So from a 1.5K bill they convinced to migrate to a R750 (don't know what the package is called) SO..... This is my second month on this contract and the second time running into issues... I purchased data, 5GB for R399 but Voice minutes was an issue... So I phoned customer service and a lovely lady sorted me out. I topped up R250 Voice minutes and R50 worth of sms's... DONE/HAPPY moved on! Now month 2 and go check my records! I have spend over a hour this morning with not one but four customer service agents, one of them in the """""solutions"""" department... Funny enough.. no solutions.... Conclusion... I was told that Vodacom randomly decides on the day how many minutes I can buy... Like a lucky draw...?? What nonsense is this???? I laughed and laughed and then I just put the phone down!! I need some proper help please someone that understands! Surely this is not a difficult scenario!? Sooo.. If I want to phone clients i must spin the wheel and see how long I can talk to them?? . I have the app and that (at this point) is just as useless! HELP ME!!!!!