3 Months into the contract and I'm still being overcharged

I am absolutely appalled by the service that I got from MTN.

Firstly, I signed why does your contact centre not have an option to speak to a consultant if non of the 2 options fit your query.

My issue has been incorrect billing from the first month I started paying for the contact i signed up for. I have been placed on the incorrect contract by the someone and the email query agent confirmed this. I have to keep following up with them, no one ever gives me proper answers as to when my issue will be fixed and when they will return the money I have been overcharged,

Some other agent told me about downgrading and paying for the downgrade....

Can someone please give me one answer and that answer should be...... We fixed our error, you are now on the correct package and all the extra money you were charged will be returned......