Not syncing at full speed

Could I please have someone have a look at why my ADSL line is only syncing at 6.4 Mbps, yet I am supposedly on a 10 Mbps line? It has been like this for over 6 months. The landline number is ***. I have logged 2 faults already (192CEK030516, 257CEK190416), both of which were closed, yet there is no change to my line speed. I have contacted Telkom support numerous times and they have tried resetting the port and recreating the profile. Still no luck. Clearly it is an issue at the exchange and not something that can be fixed over the phone. How can two faults be closed in a row with no communication whatsoever with the customer regarding whether the issue was resolved or not? I would appreciate it if a technician could be sent out to try and rectify the matter.