Had a reply this morning and it looks like the original plan is a no go. 
Yes, but I rang them up and had a chat and got them to explain my options. And so am moving my line back to BT and taking up their LLU unlimited on smpf, its gonna cost but so be it. Just got to be shot of Coms .
The problem is TTB apparently, reckon they don`t have the capacity for another isp or something, sounds like the big boys can do what they like.