Do you have a letter of engagement from your accountant indicating what services they are to provide you with?
You could express your dissatisfaction and look for a couple of years' work for free or deeply discounted, if he was engaged to file directors' IT returns and went asleep at the wheel.
But I'd assume he'd rather if you just left, rather than work for free, and how could you be sure he's not making a hames of other stuff too..?
So unless you want to look into the possibility of taking a small claims court action for whatever is the max amount they can adjudicate on, you don't have any other cost effective options...