Elod
Do you mean the Disability Income Guarantee?
If you do then this means that you are already receiving Income Related ESA and if you were receiving this from when you were transferred then I would not expect you to receive an ESA3.
I'm afraid I have never dealt with Incapacity Benefit but I would be very surprised if the reduction was not legitimate as it would have been challenged at the time.
Gordon
Nothing on this board constitutes legal advice - always consult a professional about specific problems