My bill has increased by over 1300% in one month, utterly ridiculous

My monthly bill comes to about R400. It’s been like this since I paid up the contracts and am now running month to month, until I upgrade. I specifically requested my 2 data contracts have a cap on it, once it’s up, it’s up. I didn’t really need it, just got it for the tablets for my kids, but removed the sims from the tablets. Didn’t need the data much because I have WiFi at home and work. One day, my WiFi was down, and use the two sims. R7200 was the bill for that day...what nonsense is that!?!?!? If you look at my history on the account, you’ll notice I never even reached the cap ever for 3 years...R7200. Are you kidding me? Got told, there is no cap. Logged it, they are only willing to credit R5700, and the don’t even give the full credit with the new months account. I ask about the second sim, no reply. I called, the agent refused to help because she said it was closed. No one willing to help me. Now I must spend money on petrol, to go to another person in sandton, who will most likely give me the same **** story. I’ve been with Vodacom for over 12 years, and this is what I get. And of course, they were really quick to block my SIM cards. I’m so desperate to sort this, I’ve specifically signed up to hellopeter in the hope that this gets sorted somehow.