I understand that you don't think that anything else has changed but something has to for the changes in your post to have happened.
You would only lose your entitlement to ESA(IR) if you have a partner who is working 24 or more hours a week, or your household income exceeds the amount of ESA(IR) that you were receiving or the deductions due to your savings exceed the amount of ESA(IR).
Being placed in the SG would increase your entitlement to ESA(IR), I can't think of any reason why it would result in you losing your entitlement.
Your Housing Benefit has been reduced, the only reason for this would be due to your household income or the amount of your savings.
You mention an overpayment, is there income of savings that were not declared?
Gordon
Nothing on this board constitutes legal advice - always consult a professional about specific problems
