Telkom are useless

I have a 4mb ADSL line recently installed, still having endless problems with it at this point in time im ready to tell telkom to collect there items and cancel this service will rather use wireless or 3G, my 4mb line does not run at 4mb its worst than a 56k modem according to telkom tech guy who was here its the DSLAM on the exchange and thats the last i heard of it no date when it will be fixed my faults just get closed i ask to speak to a supervisor at call center and he or does not bother to call you back or has excuses hes too busy is this the service that telkom gives its clients, is there somebody at telkom intelligent enough to actually sort my problem out