Have they checked website optimizer? Google isn't a call me and let's talk about it company. It has very efficient and streamlined tools to help people figure out what is wrong.
There's a good chance there is an indexing problem that could easily be rectified if they just check webmaster tools.
I can't comment on "efficient" or "streamlined" but I would echo this recommendation to at least create a Google Webmaster Tools account before complaining to the Internet at large.
Consultants sometimes provide a Google Webmaster Tools verification file to the site owner in question. Once the site owner uploads this to the site's root directory, the consultant will be able to access Google Webmaster Tools data on the site through their own Google account. However I've never tried this with a banned site- It is certainly possible that Google will see the domain name and refuse to show any data. Also if the site has been banned for a period of time which is longer than Google's expiration date for stored data (I forget what the time increment is... 1yr? 6 mo.s?) there might be no data to speak of. This is still ok; assuming Google makes GWT available to banned sites, all we would be looking for is a reasonable description of the problem above and beyond "we banned you for some cryptic reason".
There's a good chance there is an indexing problem that could easily be rectified if they just check webmaster tools.
(PS. Ditto on the misleading URL)