I would put money on this Touran not having a DSG box based on the poster!
I'd probally say if it is diesel it's a dual mass fly wheel problem, if any-thing.
You won't get very far with it as regards "warranty" because it's not broken, if the problem had to be brought to the op's attention, it can't be much of a problem, also if the op's husband would notice an oil leak he would notice a problem in the gearbox.
There could be mositure in the box if it is a problem, 7k a year would leave the oil in the box like muck, have we changed the gear oil yet and test driven?
Also if the op parks the car in gear after a drive when it's hot and then later jumps in and bangs it out of gear you will do sever damage to the gears.
I drove a new car a few year ago, I was under pressure and doged a it about 25 miles down a twisty road using only 2nd-4th gear, got to the house, left the car there and left it in 2nd gear, another lad went to collect it and when he did, he couldn't get it out of gear, he had to jump it out of gear. So 28k can be more than enough to do damage to a gearbox.