Incorrect billing of ADSL Fastest instead of Fast

On 24/08/2015 I lodged an enquiry on ref ***A with Telkom as to why I am being billed for ADSL Fastest when I can only have ADSL Fast in my area. According to the person I spoke to then the Line was upgraded to Fastest in 2013. This means for two years I have been paying for a service I cannot even get. I asked them to downgrade the line on reference ***3. They did the downgrade but then I receive a SMS to inform me that I need to submit proof before they will approve to pay me back that money. The e-mail given in the SMS is rejected by the Telkom mail system. They ARE Telkom...the proof is in my bills for 2013. Go through them or listen to the recording of 24/08 as the person from Telkom read the date on which it was upgraded. Then they say ok we will give you back a year's money... THEY STOLE FROM ME so no...I want it all back. Every cent!!!!! I have had enough of service providers doing you in and then change their stories. The lady said her supervisor cannot authorize payment without proof. Then she says they will give me a year's worth back. Please who authorized that???? I want my due. That's all. Nothing less except an apology more...