Have had exactly the same problems with my Q7 50 TDI from new. Took me a year to get Audi to admit there was a problem then they said they would be in touch when a software update became available. This was over 6 months ago and I'm now half way through a 3 year lease and the car is driving me crazy.
In the meantime, my car got recalled for an urgent steering issue so when Audi collected the car I gave them both keys and told them I didn't want it back until these issues were fixed. They are now telling me that they have done a gearbox software update but to completely fix the issue I would need to wait another month until the engine update was available.
After reading these posts, it seems that the gearbox update does not go anywhere near fixing the issues and that the engine update is way more than a month away so I told them to keep hold of the car until the engine update was available and in the meantime I would stop my monthly direct debit. Their response was that in their opinion, the car is drive-able therefore I should take it back and carry on waiting. If I refuse to take the car back they are going to charge me for storing the car at the Audi dealership.
The car is still at the dealership, I've cancelled my direct debit and have put in official compliant to Audi finance who are yet got back to me.
I will keep you posted.