Rust on Brand new Car

I'm driving a Datsun go Lux. I've bought this car four months ago and guess what I found rust on vehicle. I took it back to the dealership in Mossel Bay, the one salesman told me they have procedures to follow.. they're going to send my vehicle for repairs.. my question was if there's rust on a brand new vehicle with in four months how is it going to look within a year from now. I was even told when I bring my car for rust repairs.. Nissan In Mossel Bay doesn't give courtesy cars.. that's really bad service when I went looking for a car they were eager to help.