Slow download speeds?

[#1]

After finally getting all of our problems sorted out with getting the internet up and running, we were told that the line would stabilise within 7 days, we accepted that. It's now been a month? We download quite a fair bit on our PC, mainly due to my son and his games! But after checking the line stats;

Download speedachieved during the test was - 5110 Kbps
For your connection, the acceptable range of speeds is 600-7150 Kbps.
Additional Information:
Your DSL Connection Rate :8128 Kbps(DOWN-STREAM), 448 Kbps(UP-STREAM)
IP Profile for your line is - 7150 Kbps
It shows that we can download at speeds from 600-7150Kbps, but sometimes, we can be downloading at 300/400Kbps! We've only once managed to hit the 1Mb marker and that was somewhat amazing. We're averaging around 800Mbs for downloads, which is fine for small items. But when it's 15GB files, that's another thing! Surely we should be able to hit way over 1Mbps since the stats show that we can download up to 7Mbps.

[#2]

I am also having trouble with slow download speeds, just tested at 0.3 meg, tried opening a conversation with Plusnet using their ticket system and came to a halt, I replaced a wireless connection from a cable internet I have running in my house and only replaced it because it keeps dropping out and I get poor reception because of the position of my PC to the router but even so I still got 5 meg from it using the same test, love to know how to speed it up

[#3]

Quote from: suebuckby

.... We're averaging around 800Mbs for downloads....

Correct units are important.  800Mbps would be impossibly good, you must mean 800 kbps.  But are you sure that is not 800 kBps?
If you are reading the download speed off your computer then this is normally reported in kiloBytes pers second (kBps) and not kilobits per second (kbps).  A Byte is 8 bits and it's capital B for Byte and lower case b for bit.  A download speed of 800 kBytes per second would be equivalent to 6400 kbits per second, which would be a respectable figure given your IP Profile.  And you achieved 5110 kbps in the BT test, there's no particular reason why it should be much slower elsewhere.