Extreme body rust and welding falling off

Shocked to find a horrible deep rust spot on my 6-month old duster. And when I go to look around the car, found the weld fallen off from one of the doors. Would you expect this from the Renault ??? I have taken the car to the service centre and they booked a complaint. Then they suggested that I get the car for repair. I will not accept a touch up job for sure. I may have a rust bucket with touch ups all over very soon. Now they have taken the car, and have it there for 5 days while I try to find my way around without a car (very inconvenienced). They say they will touch it up to Renault standards. I have asked for the copy of the standards. Also I have asked for an extended warranty for 10 years as I cannot be driving around a rusty car after the end of the present warranty. Also need then to provide a service car whilst the work is being done.

Unable to upload the images, but they will make any car owner cry!!