Pip

hi I’m new on here. I have been transferred from High rate DLA for care and mobility to standard rate care and high mobility PIP.
The assessor came to my bungalow assessed me in bed at 930am. Everything we discussed she seemed to understand, but then her decision for the PIP rating was based on-‘observation’ I have 24 hr care with family and Carers as assessed on my care assessment.
I rang saying there was an obvious mistake, I was advised to put it in writing which I did, point for point. 7 weeks later I had not had a reply. I rang and was told it can take 6 weeks there was no letter on record, I had proof of postage and tracking had a signature and address. I had sent it to them with a copy of the letter.
i have rang numerously since to see if they have looked at it yet but can’t get through the ques are so long I get cut off over and over.
We are now another 8 weeks down the line and heard nothing 
has any one else experienced any thing of this?