Face to face assessment cancelled

I am being transferred from a lifetime award of the lowest rate of DLA care component. I was given a date for a face to face assessment by CAPITA but they rang the day before that date saying my assessment was cancelled as the assessor was off sick. They rang again that day and spoke to my husband and said the same thing, that the interview was cancelled due to sickness and offered and offered a home assessment instead the date to be arranged. Yesterday, 14th September I had a letter saying that I had agreed over the phone not to recieve the normal 7 days notice for a face to face consultation for PIP and that the consultation was scheduled for 12th September, which was the date of the original assessment which they cancelled! The letter was dated 9th Sept but I got it on 14th September. I have never agreed not to have the 7 days notice but apparently CAPITA are deciding my claim without a face to face assessment. Please can you advise me about what to do I am so upset.