Vodacom worst service ever

Vodacom provides the worst service ever. First they cancel the incorrect contract, and then they end up charging me R100 more every month for the contract they incorrectly cancelled and reactivated on the incorrect package, this has been going on for longer than a year, after we phoned numerous times and logged service requests. This morning I checked my balances and I received less than half of my usual minutes, sms and data, but I'm still having to pay R100 more every month for something I didn't even sign for. The service is ridiculous and I am beyond fed up with vodacom. Why do I sign a binding contract for 24 months if vodacom just ends up changing premiums ans packages like they want, and I have to phone around like a idiot everytime and it still doesn't get me anywhere.