Help been tricked to changing

A man came to my door with a badge stating he was got fitting meters for the government and turns out iv now changed suppliers I do not want to leave bulb and can’t get through to them to cancel it was like 2 hours ago I have 14 days. Can build refuse my transfer as I am not leaving

In the meantime if it were me I would cancel any direct debit arrangements, email them and keep a copy.
Which company was it?

@1988amber I can see that we have cancelled the switch away from us and are blocking any subsequent attempts.