Adsl service remains intermittent

We have been experiencing an intermittent service on Adsl for quite some time. We report it and Telkom reports that it is fixed. It then functions ok for about a day and then the problem restarts. When I phoned the Telkom service line they informed me the problem is with the exchange and that is not in their control to get it fixed. I fail to understand how that is my problem. I require a running service. I would like to know how I can get a more holistic resolution to my problem