A lot of the time the multitronic gearboxes can actually be repaired. Ask me, I've had mine done twice!!
The first time my box failed I took it to Audi Airport and they quoted me
R118k to replace the transmission. Seeing as that was more than the vehicle was actually worth, replacing wasn't an option. I had a Motorite maintenance plan on the vehicle and they paid R28k to have the box repaired. Well, basically to replace the ECU!
The box failed again in December 2013, out of warranty and again the ECU was replaced, this time at a cost of R21k!!!
The challenge is to find a decent mechanic that can service the vehicle, out of maintenance plan and do a good enough job of it without breaking the bank.
Martin Le Roux motors in Honeydew is one such service centre. TorqueTuning in Krugersdorp is another.
For gearbox repairs, Erlemanns in Laub street downtown JHB are the ones to use...
If you choose to do your out of warranty servicing through the Audi service centers prepare to pay ridiculously inflated rates.