Hmmm... just noticed something from one of your earlier posts about how your GP was supposed to fax something over but it didn't get to the DWP in time.
Are you sure your GP surgery fucked up? Or could it be possible that your GP surgery did send the fax but the DWP lost it/didn't attach it to your file or whatever?
Can you check with your GP surgery and ask if they filed the fax confirmation slip in your medical records? If they did send it and if you can confirm that it was sent (to the correct fax number) maybe your MP can help you get the decision overturned?