TDI engines, and all direct injection diesel tend to consume oil and even more if you squeeze them. So if you make a "sports" or abnormal driving you should check the oil periodically. If not, you must control the oil, and the other levels, periodically, as in all vehicles that are now in the market.
When you say that the car in 3000 km has no drop, what do you mean? that the rod is wet, that the oil is in the minimum mark?
I remind you that from the minimum brand to max. There are only 1 L. of difference, that when the oil marks you to the minimum rod, in the engine there are still 4 l.
If only the minimum is a consumption of 0.5 L., not at all abnormal.
If you have to add 2L. of oil or more, that they check the car because there is an abnormal consumption (rings, bearings, etc.)
to make a claim to the brand you must first contact customer service; You will lose time and it does not help much, just to open part of your incidence.
The second step is to tighten the nuts to the post-sale chief of the concessionaire where you bought the car, always knowing what is demanded and demanding a solution to your problem, obviously documented before or will laugh at you.
The third option, if the last two fail, is a claim to consumption that you must document well if you want them to accept it.
All the best.