Call to Customer Care never get your there. Charging more than what my contract is.

I have been trying to reach out MTN customer care(135) since morning. It is very disgusting experience. it says "wait for Next MTN Champion". then after 10 seconds call becomes silent. No response. They over charged my account. I took a contract for 199 rands a month. but they started charging me 280 rands every month. this month 310 rands. it is a data contract. How can they bill me what ever they want. It is cheating. Very Soon you will lose customers like me. Pathetic MTN. God may bless you.