Wow still no AOR, that should be hard. Are you sure the file is actually with them. I mean am sure you tried the GCMS notes, webform, direct mail and even the MP. I wonder what else could be done because even immigration agents refuse to touch already submitted files.
Maybe one day find time and go through all your submitted files if you have them and see if there is really anything missing or suspicious or lost. Or any misrepresentation, just trying to give options but don't know what one can do hopefully one cam give you better options. The sponsor especially should review all answers and information presented to them.
