I'd have thought you'd have added the Gas Board to your list of bitterly hated organisations.
'Their' fitters are self-employed and the services of all were recently dispensed with and they were offered altered contracts which were contentious.
Anyway, I used Paul Maddocks' Heatforce for the work. They were the cheapest and able to do the work before Xmas.
That's competition for you - and a lesson in economics.