20Mbps ADSL service advertised in a 4Mbps max area

I checked the Telkom ADSL coverage in the Gerdview area on 06 Feb 2016 to confirm that they still offer 10Mbps ADSL connections before upgrading my 4Mbps line through Axxess. Upon checking the service availability in my area, I found that Telkom advertised 20Mbps connections, whereupon I proceeded with a request on 06 Feb to upgrade to 10Mbps through Axxess, who manage my ADSL connectivity and Telkom ADSL line component. The following response was received from Axxess on 08 Feb : \Good Day Unfortunately Telkom are not allowing us to request the upgrade due to your adsl line not connecting to a MutliMode card but to a GDMT Mode card. GDMT cards only support up to 4mb speed. We have removed the upgrade request\".<br> <br> I am extremely disappointed in Telkom advertising line speeds of up to 20Mbps in my area, while the area only support a fifth of this speed. This is misleading and Telkom should update their coverage map to reflect the true status of their service capabilities for this area, as well as any other areas that may be misrepresented."