Well, it seems they forgot about me.
After calling for the past few days, I got through to a helpful lady who said my handler was not available on the phone, but had a chat with her in the chat room.
My handler called me back after reviewing the photos I sent nearly two weeks ago, and advised that as my fuse board has no available slots, I need to arrange for a Double Pole Mains Isolation Switch to be fitted before they can work on it.
Spoke to one electrician who can come and take a look in the next few days. Spoke to another who advised that it is not legal to do that as it requires removing the main fuse, and that it is the electric company that needs to do it.
Western Power are currently closed, so will call them first thing tomorrow. I think it is going to cost about £200 with them. Electricians may be cheaper, but not sure it is worth the risk?
Once this is fitted, they can book me in