Inadequate response from telkom

I have noticed via telkom service query map that houses on my street have a maximum of 20 Meg's adsl like service however the half of the street that I live on have a maximum of 10 megs.i have written on telkom Facebook to query the reason as to why only half the street can get up to 20 megs and the other half only up to 10. I have continuously been told that a technician will call me however no call has been received . I repeatedly asked why no follow up has been made and am constantly told someone will contact me.