You have 2 options, repair or new.
http://www.eeuroparts.com Part # 01P927733CM $894.99
http://www.autoecu.com
My understanding is that a TCM unit from another VW will work. There was a long discussion last year about the TCM and not being available, discontinued. If you have a bad TCM, you need to look above your unit to see if water has leaked down from your front windshield. This is what has caused the TCM to go bad.