Worst service

I have been trying to upgrade my one line and stating there is an issue with the account, Vodacom contacted me to advise the will give me discount on my data contract, but now its more and not less, I've send an e-mail with no response, when you phone you don't get hold of anyone. Vodacom is ripping clients off with their over the phone deals they provide and then it's not the deal at all. I have 4 lines with vodacom and this is how the service is.