I phoned the ATOS number given on 06/02/15 after my consultation was cancelled at the last minute.
To cut a long conversation short the lady on the phone said she couldn't find any appointments nearer than 30 miles to my home and after 10 minutes on hold said she would put a new appointment in the post when she could find one.
That was 13 days ago and I have received nothing. My disability is escalated by stress (Sarcoidosis) and my blood pressure tablets have been doubled because my blood pressure has gone up to 164/103 at last GP visit.
Speak to your GP, if your problems are being made worse by your having to wait, they may be willing to write to the Assessment Provider to request a home assessment.
You can also contact your MP to see whether they can help.