Advertising 4Mb Uncapped line but Actual (450Kb/s)

Currently paying for a 4mb uncapped line and speed test showing speeds of Download - 3.40Mb , Upload - 0.4Mb and Latency 120ms.

When downloading small or large files, watching movies/series online, showmax, dstv, Youtube etc. my actual download speed im recieving is only 450Kb/s MAX. I was told by telkom consultant that it has to do with the hosting server im using to download etc, seeing that the speed test is successful and nothing is wrong with the speeds, Well i beg to differ. Correct me if im wrong, but if the exchange server or hosting server is the problem causing the very low download speed then surely this speed of 450kb/s should differ from website to website and not have the same average. I was given a test account to setup with my router but had the exact same speeds and once again the consultant tried convincing me that the problem is not telkom based, but it is that of the servers i am using to download or stream.

I am getting exactly 10% of what im paying for. What is happening to the other 90%? I am not being credited for the loss. Something drastically needs to be done to resolve this as this query has been open for 1 week already. Absolute nothing is being done to rectify this problem as the ball is being thrown into my court every-time a consultant call's me.