Thanks for coming back to us @GeoffTownley, you did ask for a visit to be arranged. I can cancel the appointment for you from here.
Regarding the location of your telephone socket, do you have a brown omni-box on the outside of your house?
If so, can you follow the cables that come into your home?
Also I have looked into this and your area looks like the home phone change over will be happening in June this year.
Regards,
Steven_L