Telkom technician bad service

I app**** for a adsl line 5 weeks ago the technician came to my premises for 5 minutes and left did not come back and till today my line is still not activated and yet Telkom sent me a bill via post already I have been to Telkom branch about four times asking as to when the technician will be coming to install line and still not getting any positive feedback.. What can I do to get the problem sorted out...