car jumps forward when I try to move

[sainy]

Hi Guys

My audi A4 automatic (2002).

When in D and I try to move forward and I lift my foot off the brake, car jumps. Sometimes it stalls other times it will jerk couple of times before moving of.

I was told it is transmission oil and filter. I spent £85 getting that done. Problem still persists.

Any clues guys, what could be?

Thanks
Sainy