UC50 assessment

Hi Gordon. My husband received his WCA 29/9/20 and asked if I could be added to the call of which the assessor did. I asked if she had read all evidence sent in which she stated she did not see the letter that was sent in 6 weeks before phone assessment. I told her it was sent by Special del then she stated she was working from home and it went to office. I asked her to reschedule until she read letter that stated reg 29 and reg 35(b) she ended the call and contacted DFC to state that my husband failed to participate on the grounds that I refused to hand him phone. This was a complete lie. Since then the DM failed him under reg 45 and 42. I have since requested MR and SOR. I have requested several times copy of Assessors report copy of FFR4 form stated within SOR . The case manager within UC journal said that he couldn’t receive I stated it formed part of the outcome decision and he is entitled to see it. After weeks of demanding this he received another journal entry stating that information sent in post. Today he has received letter from DP team stating he has to wait 28 days . He is on long term (10yr) enhanced rate PIP for both components and they have sent him letter from UC stating that under reg 45,42 he just receives UC standard rate. He previously had premiums under IS on joint claim but change of circs had to claim UC. I have requested within MR reg 21 Re previously claimed support components to be taken into consideration for joint claim the same way SDP for single claimant. Please help. Thank you