Bad customer service and lies at vodacom

Early this month I complained about vodacom billing my account with high amount. An they called me that they will fix the issue but clearly they never did that because even today my account it's very high which I don't understand why. Even then when they checking they also don't understand why my account is so high. Vodacom is useless I don't wanna lie it's very useless. I will never recommend it to someone else. There is a sales person by the name of Akhona, she is the one who was assisting me with my contract and she puts lots n lots of things in my contract now she doesn't even understand why is like that. Unfortunately even there management they can't solve it as my account is always higher and the agreement was to pay R 989 every month. But now as we speak I must pay R1500 for what. Can someone please solve this ******* at vodacom