3.0 v6 tdi multitronic gearbox issue

Hi all, new to these audi automatics, I have a 2005 audi a4 3.0l v6 diesel auto.... I'm having a pain in the backside with the gearbox at the moment. When the cars been left or its cold it doesn't select gear, if I put it into drive it stays stationary and counts up the gears to 6, same in reverse it doesn't move, after about 20-30 minutes of letting it warm up and stop and stating the engine it'll start selecting and moving, I haven't run the car for over a week now and it's taken nearly an hour to budge anywhere, has anyone else has this same issue? Is it a matter of an ecu reprograme or new gearbox?