I guess the bank can do what they like to you with regard to your banking arrangements with them. Which bank are you with, and what benefits will you lose if they do change the account?
Hi, our bank did this once it found out we were in an IVA, i don't know exactly how they find out, but we got a letter saying we were being dropped down to a basic account.
This meant we couldn't use all cash machines, only RBS or natwest ones.