Hi.
The Multitronic is arguably the worst automated transmission that the VW Group could have produced, and it sounds like it's experiencing a complete transmission failure.
I recommend you sign up and describe the problem.
http://multitronicforum.de/viewforum.php?f=7
I know that there are specialists in this forum who can repair these transmissions for a portable device. Do some research or ask around. With Audi, you'll only hear the term "AT," and that will cost you 6000 euros plus additional expenses.
Best regards, Rüdi.