Don't Upgrade your vodacom contract its a ****

I would like to cancel my contract. This network is trash... For the past two years I didn't have a problem with network and was willing to pay the ridiculous prize for the guaranteed network. The worst mistake I did was to renew my contract two months ago where I was promised double the data for the same price since then I can't even use this data. I am even being hotspotted just to send this message. I use the data for work but as it stands I can't use it which defeats the purpose. I would like to cancel this contract immediately.