Advice regarding ESA MEdical

I regularly care for a family member who is disabled and has been in receipt of ESA support group for the last 8 years.
He was supposed to attend a F2F medical on Monday 3rd Dec however they called an hour before to cancel which was incredibly lucky because he had not told me about this appointment and clearly was not going to attend. He has mental health issues and does not understand the consequences of actions like not attending these appointments however he has incredible difficulty leaving the house.
I have absolutely no idea how I am supposed to get him to attend this medical as he is incredibly anxious around new people and going to a medical centre surrounded by people is simply not going to be possible.
Iv looked into the possibilities on home visits etc however doctors notes are required for these and its just as impossible to get him to attend a doctors surgery as it is a medical assessment which is a catch 22. I did assist him with filling the ESA50 and I felt it was very thorough and I clearly detailed the difficulties he faces with out outside world and even sent photocopies of his prescriptions to show the medication he is on which in itself should mean he is ineligible for WR activities based on exceptional circumstances. I even wrote in the box that regarding issues with medicals that I would like to request a home visit.
Iv never claimed benefits personally and have no idea how this process works but looking online at the multitudes of terrible experiences people have encountered it has got me incredibly nervous, especially when I hear of people in similar circumstances being awarded no points at all.
Another letter has arrived today with a new appointment for the 21st december first thing in the morning which is also impossible for me due to work.
I have no idea what I should do and am very fearful for his well being, is there anything I can do or will I have to drag him kicking and screaming to this medical assessment and get time off work to attend.