DWP have not contacted me with their decision?

I had my f2f on 19th July. A couple of weeks later I had a letter saying they have all the info they need to make a decision. Since then I have heard nothing. However, I do know their decision because I had a letter from my local council to say I no longer qualify for help with council tax. I called them and they explained it's because I only qualify for standard rate mobility. So I called DWP in tears because prior to this I was receiving DLA higher rate mobility and middle rate care for life! My disability is congenital and will never get better, only worse with time. The man I spoke to at DWP said he could see that I had not been sent a letter and would send it out. I also asked for a copy of the f2f meeting because I recorded it and wanted to check what I said was written correctly to them. He said he would do this also and send it out. That I believe was 29th Aug and I have not received anything at all. I feel I can't move on through the process of appealing because I haven't legitimately been told what their decision was.
What should I do next? I have received the usual payment on the 11th Sept so I don't know what is happening.
TIA