No AD would or will refinish your Titanium case- Reasons? -- They just don't do it.
What did I do with my PAM 305?
-- I used a pencil/pen eraser, using the pen-side of the eraser on the case and everything was restored back to normal. The only difference was that the color where I applied the eraser was a little bit clearer than the normal case color. Don't worry, Titanium case regain a nice work patina pretty fast (if you use your watch in water)
My 0.2 cents.