Esa assesment

On the 1st of March 2017 I had the re assesment appointment through the post for an appointment on the 13th of March. Currently in SG for PTSD from the services and have severe anxiety and suffer from chronic cluster headaches. I phoned the advocacy service to see if someone could accompany me,whom I have dealt with in the past only to be informed no one works mondays and are unable to assist new clients. Bit strange that as they helped me with my late father. Not to worry, I'll re arrange it. On the 16th of March a new appointment was offered to me for the 4th April also accompanied by a letter saying,do not attend this medical as it has been cancelled. Bit strange I thought so I phoned the health advisory service up to see what was going on and they informed they may have over booked and to wait for a new appointment in the post. I also had the same response from the DWP. Smelling something untoward was going on I went to the CAB today and after a few phone calls from the highly professional advisor, the DWP had told her that my claim for ESA would end on the 4th of April. Both departments, the health assesment centre and the DWP both blaming me for cancelling the second appointment which clearly isn't the case as the letter I have from them states"WE NO LONGER NEED YOU TO COME FOR THIS ASSESMENT". The DWP told the CAB advisor I can put in a mandatory reconsideration . Now I may be from a different planet but why should I put an MR for something which is clearly an error on there behalf. Am totally beside myself.