Volkswagen Polo 2015: GTI DSG issues

I purchased a new VW Polo GTi 1.8T DSG in May. It ran great for the first six weeks, but recently it has developed a thunk/thump noise when shifting from second into third while using the paddle shifters or in semi-automatic mode. This noise does not happen in 'D' or 'S' or in any other gear. I took the car to the dealership and took a senior mechanic for a drive, who on hearing it agreed that it was a problem and that I should return to the dealership. On returning the car to the dealership, the mechanic and service advisor had a discussion between them and I overheard something mentioned such as "do the normal reset and software checks then probably a disk pack/plate". The car has been back to the dealership to see if they find the fault. The latest update is that VW has advised the dealership to replace the complete gearbox, and new one is being shipped out from Germany. I would consider this to be a major failure of the car considering it's only six weeks old and has done only 1700 km. I am really annoyed, the car is only six weeks old and had only done 1700 km, and already it has a major fault. Do I have any rights in regards to getting a completely new vehicle?