Claim for PIP

I am my sons appointee, my son who is now 21 years of age was in receipt of DLA for a number of years and was awarded the higher level for his personal care, however Dec 2015 we were sent the PIP forms, I completed the forms and sent medical evidence from all his consultants, I never worried to much as I always believed my son would automatically be awarded the enhanced payments. After filling in the forms we both  went along to the medical assessment, many lies were told on her behalf to the DWP I could not believe it when we were only award 2 points we took our claim to tribunal, this claim from start to finish took 13 months. My son has had medical problems all his life and  learnt to live with them, he is both bowel and bladder incontinence he has to use an enema's regularly so his bowel empties he also has to use a catheter throughout the day and attach a bag every evening to collect his urine as he has problems with his kidneys etc  to me this critea alone should have awarded him 8 points but as he manages he was award '0' points, another critea was managing theraphy - weekly this takes him well over 7 hours to me he should have been awarded points, again he received '0' points as he is seen as managing and not being assisted. I feel very angry as I have tried to make him as independent as I possibly can and now feel he is being denied a benefit which I feel he is fully in titled to, my son also has to inject himself daily and has to take life saving drugs daily and when he goes out he has to carry with him an emergency injection pack and wears a medic alert bracelet, my son still requires a lot of input from both myself and my partner with his everyday living even though he is at university he has other problems with in life to cope and never complains, I am so proud of all he has achieved but after the initial interview my son felt for the first time in his life felt so degraded and useless this angered me so much  as she even asked him when he replied honestly to one of the questions she asked was bluntly 'are you mental' as he needed help with certain things in life, the questions asked were more about his ability  and not really focusing on his medical problems that he faces daily, the lies reported on her behalf were unbelievable and I felt and still so angry that they are allowed to do this, now  after 4 months after going to tribunal  we are applying for the second time sadly my son does would rather not. I have posted this comment on here with hope the something will change, it seems to me unless you have a mental problem or go down that road PIP is an impossible benefit for those who have medical problems and are seen to be managing them alone or living independently are being denied what should rightfully be theirs. I wish I could do more for all these people who are having the same problems as my son, I have written to the house of parliament and my local MP but don't seem to have had any luck. Changes urgently need to be made to this benefit,  people should not be made to feel inadequate  or degraded by this government, sorry it just angers me so much.