Welcome to the Community @kim-21,
You unfortunately have met bits of the utility business that often seems to operate in ‘cowboy’ mode requiring a sense of scepticism at every step.
I moved your post into this one about demand tariffs and prior posts might be helpful to understand it better.
You are not ‘trapped’ excepting for the time it takes to organise another retailer and plan. Last year I changed my plan (not demand tariff) to CovaU and they changed the rates even before the switch - a change I immediately cancelled.
Caveat Emptor and reacting quickly has never been more important.
This other post might be helpful?
