Doo, I know it seems a bit confusing, asking one question and getting a million different solutions, but in essence everyone who mentioned somethign here was 100% corrent, and if you took all those measures to get your frame rate down, multithread, antenna etc etc it would definatly improve your performance.
However, it seems to me like you use Internet Explorer to browse the web (please tell me I'm wrong), because your telkom test is 1/6 of what it could be, sometimes that happens with single threads, I'm gonna make another assumption, when you download a file it probably sticks around 20 - 30KB at best and NEVER jumps over 40KB/s. Am I right? If this is the case the quick solution is as follows (and its a toughie because it requires you change your web habbits, but I'm positive it will work):
Use firefox, not only does it draw pages faster after downloading them, and not only is it safer then Internet Explorer but it allows multithreading, what this means is if the maximum you can pull per connection is lets say 25KB/s then if you open 5 requests for one file and download 5 different parts and put em together later you could get 125KB/s... alot of users have used this to great effect, however you will need to config firefox a bit before it is efficient with multithreading, here is a step by step guide:
http://devnulled.com/archives/2004/12/how_to_make_firefox_faster.php
OK that shoudl take care of browsing and small browser downloads (10MB or less) but what about bigger file downloads, for that you need to again multithread, but this time you want something beefier, here are suggestions:
Download Accelerator
FlashGot
GetRight
Now you should set the download manager to download with 10 threads for maximum efficiency, it pays to use this wether you switch to firefox or not, it really helps. Alot of iBurst users never get more than 40KB/s on a single thread download but if they use say 10 threads can max thier connection (120KB/s) anytime of day.
The reason you might have not had problems before but do now is because WBS are still playign around with the shaping rules and bandwith manager, give them time, there are still alot of kinks but I'm sure if you follow those 2 steps you will be able to get faster speed today and finally have the connection you thought you signed up for, I hope that helps.
P.S. if perhaps it is the midrand tower, or even your quality of signal to the midrand tower (you can have 100% signal and still have a bad frame error rate) then you might want to look into the external area to boost signal to midrand or even to connect to a different tower alltogether.