I think Josh would test his work before he sends you all back. But like you describe the issue it sounds like a Skreem problem. What do Josh sayed as you mentions the fix he has done don't work?
I think you have only one keyfob? So that it can't locked/unlocked the doors that can have a few issues, first the batteries are empty, second they have to be synchronized with the Skreem, third the rf of the keyfob is dead or the rf of the Skreem is dead.
Maybe my Skreemulator project can help you? With the Skreemulator you will replace the original Skreem, get two RF controls to locked/unlocked the doors and can use simple mechanical keys. No transponder is needed in the keyfob any more.
The Skreemulator is available in the US right now, I will make a other post with all details later.
For a first look you can klick on the link in the bottom of my post.