That's a shock. I figured they won't be it unless you could verify that the work was done.Well, one option is to just stop by your Audi dealer and let them do it.
After I saw your question I called a nearby Audi dealer....they said, "of course we'll do it.....at no charge."
That should be the first thing to do, some dealers will do it, some wont, all depends on their own individual approach to servicing a customer. Some will do it just so they can generate a lead for a return (paying) customer in the future.Try giving your dealer a call and see if they'll do it for free?