dla to pip at 16

Hi, this is my first post.

My son turned 16 in September and we are currently going through the changeover from dla to pip.

I have filled out the form explaining how he needs help with everything! Except physically moving about!, we can't even leave him in the house alone!.' I am dreading him leaving school as I really don't know how we are all going to cope!.

My concern is the face to face assessment! I am his appointee and will go with him but I have read posts from people online that say the assessors may not listen to anything I might say! He does not realise or accept the help he needs and will outright deny some things. Do they understand that people with asd think differently? That in their own mind/world things are different to the people around them?!.

My son will come into the room sometimes and we can tell from the smell he needs the toilet so we will prompt him to go!, he will sit and deny it, making the sofa smell long after he has got up and then when I pick up his clothes later they are badly soiled!!. 

If they won't listen to my opinion when I am the one who lives with him then what can i do?. 

Thanks for listening