I tried Audi for the black ring badges and they told me they don't make them (as Tom said above).
I bought mine (matt black) from ebay over a year ago - just bear in mind that despite ordering the correct size they're v slightly smaller, not an issue on the back (remember to mark out with tape where to place it, middle of the boot etc) but on the front you'll see a 1mm or so gap to the holder on the grille.
I looked at several sellers when I did mine and the feedback was the same, that they're slightly smaller. However they look way better than the chrome ones on a black car