Vodacom issues

I have problems with Vodacom for years now, the network is so bad that we can't use our data, data we paid for and every month Vodacom take the data. I have so much proof of all the correspondence I had send to them. Have screenshots of the bad network. We must keep paying but can't use the service. Every time they said that the matter is resolved but it's never resolved. I have ask them several times to stop my dad's wifi, but they don't. Where can I get someone who can help with this issue please. I am fed up.