They will never return the money. Work has been done, plus they have his money anyway. It's almost like they are forbidden to return it no matter what.
As mentioned, the rust proofing will have no effect on this. That warranty and extra work is to protect the vehicle from the inside out. Even if it covered rust on the painted surface, this wouldn't be covered since it was your fault Warranties don't cover user error, they cover defects in the product.
My suggestion is find a new parking spot, and use your mirrors when you park. Most people are as careful as humanly possible when they just get a brand new car. I'd hate to see what the next few weeks have in store for that 3.........