Clearly something has gone wrong with the process, you should have received written notification of the appointment from the Assessment Provider, however, I do not think there is any skulduggery going on! Home assessors do not appear to have control of their diary which is kept very full by those who book the appointments, so I do not think that the assessor would have been there if they did not think that they should be.
the doctor was very embarrassed when he was told that we were not told of appointment and made a note of it I do not in any why blame him but after doing a bit digging myself this is not a rare phenomenon either this is a genuine problem with in the system or the people involved are just not bothered we are asking for a reason why alone side our mp as this I feel happening once is too many after all these people are on a lot of money too do this job and what would have been the out come if you have mental disabilities.