Sometimes good things happen to bad people.
But the experience and advice still stands. Don't worry too much about LUD's they aren't worth the bandwidth they occupy. Here is the process I followed, again, not sure if it garnered my approval, but it definitely dint harm it:
1. Send a fax with an articulate letter asking for the approval, and completion of all formalities.
2. If you don't hear back from them in 3 weeks, repeat 1.
The pattern so far seems to be an initial letter/call/fax saying get off our backs. But the experience so far has been good in terms of something good transpiring due to the faxes. So I definitely advice you to keep the pressure up.
LUD's on the other hand are a joke and need to be treated as one. Doesn't hurt/harm if your file is touched or not. The system is notorious for being inaccurate. So even if your case was touched it might not reflect the LUD.
Missing cases on the other hand are a totally different story.
Good luck with your approval.