Over charging

I have contacted Vodacom twice in recent months, due to them over billing me and not adhering to the call limit I have in place. The call limit has activated for a few years now and recently my bill has doubled due to out of bundle data rates. This is also strange considering, I have fibre at home and don't really use my data at work. I called the call centre today and was on hold for approximately 40 minutes and then only to hear that the website does not reflect correct information and that sometimes the call limit just doesn't work!! So why offer this service? I was promised a call by the manager this evening and I am still waiting!!!