Highly annoyed. Beyond poor service

I feel beyond frustrated with the company Vodacom. About a month ago I have contacted them.to switch to paying cash as being under debt review no debit orders can run against my cheque account. I even changed the date of when I will pay as paydate has changed. To my greastst grievance they did not change a thing and debit my account and charged me interest. But it is not all. In November I received a statement thst my balance due is R 504. And thst I had a credit of R 750. On the 3nd of December I went to the ship to pay R510. This payment os not even against my account yet and the bright callcentre agent told me I am behind which I am not and thst there is was no credit in my account in November. I need this to be resolved as in the end of today. And your call centre agents need better training. Highly annoyed. Cannot even cancel my cellphobe yo switch to pay as you go and keep my number due to the contract!!!