Had similar problem with mine and was told it was already on 2MB but was getting less than 1MB
All i did was open command prompt and type ipconfig /release
followed by ipconfig /renew and it fixed mine.
Now i'm not suggesting it will work for you or even that it worked for me [it may have just coincided with NTL swapping me]but after that i was on 2MB.
As mentioned phone CS and chase them up,it's rapidly becoming a hobby of mine calling CS we are on 1st name terms
