What have i done!

[#1]

Can you run a speedtest at http://speedtest.btwholesale.com/ and let us know the results?

[#2]

Quote from: jfaux

As ive already stated,i use exactly the same sites etc as i did with BT so why once i switch to plusnet is this happening?

Hi Jfaux,
Welcome to the forums - sorry to learn of your difficulties.
The short answer to your question is that anything can happen to your PC at any time - whilst remaining with an ISP, when changing ISP or after you have changed ISP.  If PlusNet tells you something is hammering you UPLOAD then they must be right as they can measure your usage.
If you want help, there is a great deal of experience around here upon which you can draw freely - please give consideration to the advice offered by OldJim - he is a wise old owl!  
We all have choices in life - sit on the side lines bitching about something or get involved and make things better for ourselves and others - it is for that reason that this forum is rich in community support.

[#3]

You've not got any Apple software installed have you ?
We've seen instances of huge uploads when it has got itself in a tizz - a bit of a stab in the dark but it has happened before.
I've had connections with other ISPs which have ground to a halt when large numbers of peers have connected to my machine using P2P networking.