KEEP BEING PUT THROUGH TO PEOPLE WHO CAN'T HELP

About three weeks ago we upgraded our 4Mb/s (50 GB cap) line to a 10Mb/s uncapped line. Two weeks ago we received an SMS stating that we have been upgraded to an uncapped line, with all our new details, which we then inserted into our router. The speed of our line had been decreased to less than 1Mb/s and okay we have an uncapped line now, but We are two people living here with an Explora and my computer runs 24/7. I am a programmer which means I need the internet speed at the highest it can be, for research. I called the Telkom call centre but they put me through to 4 different departments, all stating that I am on a 4Mb/s line, and I told them that I upgraded to a 10Mb/s line then they would put me through to a different department. When I upgraded they told me it should not take more than 7 working days to finish the upgrade, those days have been over for a while now and all we have is an uncapped line and almost no speed. They keep telling us to log a fault which we have done twice already and each time we do we get a call stating that the fault has been fixed, but it hasn't.