i have 2 seperate bt boxes one for phone and a seperate one for my bt infinity,could i ask bt to take away the telephone one but just keep the internet one?

I'm going to assume you mean the sockets that you plug your modem & phone into. I don't think BT will, they might for a fee but it's highly unlikely.

Just exactly what do you mean? Do you have two separate lines, ie pay two lots of line rental and possibly also have two different phone numbers?

Or do you mean that you have two phone sockets in the house? One that has the BT Infinity Home Hub plugged into and another with a phone plugged into it?

If you have the former you can cease whichever line is not carrying the Infinity service and just keep the line with Infinity.

If you mean the latter then one socket is very probably just an extension of the other. Both are connected to the same line. So if you cease the phone line you will also cease the Infinity service as both phone and broadband are delivered over the same pair of wires.