PIP assessment

I was due to have a home assessment on the 19th February. Capita cancelled it due to assessor being ill. It was rescheduled for the 2nd March. Capita again cancelled but no reason given and rescheduled for the 3rd March. The appointment was for 11.45 and present were my two sons and an independent witness who'd come to support me due to my anxiety. One of my sons sat by the window watching for the assessor. At 12.15 when no one had come I rang Capita to inform them the assessor hadn't come. They told me they'd put me on hold and contact the assessor to find out where they were. A few minutes later they said they'd been unable to contact them and to wait until 12.45 as they could be running late. At 1pm I called them again and this time was told the meeting would not now take place and would be picked up by the 'back office'. They asked for a description of my house and told me to ring back the following week. When I rang yesterday I was told the assessor had knocked on my door and got no reply. I told them about my witnesses and the fact my son sat watching out the window and no one had come. I was told my claim had been sent back to the DWP as a none attendance and suggested I ring them and ask them to return the forms to Capita. I have tried ringing the DWP for 2 days for up to 45 minutes and not gotten through. I am very distressed over it. Not only was I in and waiting, but my husband had brain surgery in December and is at home recovering and cannot be left alone so there is always someone here. Also, she said the assessors description of my house matched the one I gave them. Well I'd said my front door was black. It's black and white and on the day was fully opened in order to hear anyone so the door the assessor would have had to knock on was a fully glass one. I suffer with depression and was already stressed by their two previous cancellation so to now have this happen is awful.