Vodacom overcharging

I have been with vodacom for many years. Now they are overcharging me over R2000 a month. They even charging me for fibre even though their fibre is not working for 2 weeks now to date. I was paying R190 a month to get vodacoms free 290 minutes. When it was time to upgrade they said I will now pay R290 for their 290 minutes plus get a free Samsung 02 cellphone. Now they charging me for that free cellphone plus they charging me R419 for 410 free minutes which I never agree to. It just doesn't add up when my bill was around R637 end of last year. They adding their own amounts in my bills. When you have one or two contracts with them it's fine but other than that they overcharge you when you have more contracts. If they don't overcharging the their payments will start bouncing because im over going my budget.