Incorrect billing ongoing for 2 months

I changed my internet package from the Telkom Simple Plus package (4MBline 20GB softcap - R499pm)) to the Telkom Do advanced (4MBline uncapped - R585pm), the first time I called the call centre (end of March 2015) to implement this they changed my package to the Telkom Do basic (2MBline Uncapped), when I called the call centre the consultant seemed very competent and told me that he corrected this error and that I am on the right package now which is the Do Advanced for R585pm. When I received my invoice my bill was almost R2000, this was not correct so I called the call centre only to find out that the \so called"competent consultant put me on a Telkom Home Elite package (20MBline uncapped) at a subscription of R1500pm. After logging a dispute to have the invoice corrected"