Are there any special numbers in the UK that are "not available" "busy" "congested" etc so that I can test to make sure that I am playing the correct tones back to the user ? At the moment, I am getting a boatload of "reorder" / not available when I know that the line was "engaged" or "busy". Trouble is trying to track it down because the line is not always "engaged". Does BT have any special numbers to call ? Julian