Sounds like you are getting what you are paying for !! -- 30KBs == 240Kbs so right inline with a 256Kbs connection speed (figure you also have some other communication going on the line in addition to the download) -- So if you want faster downloads you'll need to upgrade the service contract to a faster speed (256 Kbs is a pretty slow connection speed nowadays)
For example Here is my speedtest result in Kbs :
and in KBs :
TO illustrate the difference between Kbs (bits) and KBs (bytes) Note this is 2 seperate runs so the speed is not exactly the same or would be divisible by 8 to change from one to the other but is close enough to show the difference in reported results !!