I would go to the hardware store and buy a range of steel wool, about #3 down to #00. Experiment on an out-of-the way spot on the appliance, and determine the right coarseness level to duplicate the finish. Rub only in the direction of the original brushing.
If you master that, you can go coarser, coarse enough to take out deeper scratches, then work back to finer, and blend in with the finish. To get a perfect finish you have to vary the angle of attack by 45 degrees or so each time, so you know that the scratch and the coarser marks have all been fully removed before going to the next-finer grade. Finish with strokes in the direction of the original brushing.
I'd request a replacement since you're not the one who scratched it. That said, I live with the very minor scratches I've got on my SS appliances, and clean it with spray furniture wax. I like lemon pledge, just for the scent. Any spray wax polish will do the job. Very easily, too!
I disagree with what has been said...Stainless steel is very hard...
you need to go to the "installer " , and demand that they re-polish the metal..if they refuse ,ask for their certificate of insurance, contact their insurer for, file a claim for "completed operation"' and demand a new range....if it can be repaired great, , but if damaged beyond your satisifaction, again demand a new unit. I am not a lawyer, but have had a similar experience with a $5k range.I got a replacement , without scars!
I don't think our SS range top was in for even a week before Mrs. Mikie scratched it. In the scheme of things, stainless steel is on the softer side and is fairly easily scratched. I have a SS grill and it only took one time of setting something on the table extension on the side of the grill to get light scratches on it.
The issue with SS is that it's difficult to match the factory finish. Our SS appliances all have some sort of "brushed" finish, a grain if you will, and if you try to polish out the scratch, you will not match that factory finish. Stainless Steel cleaner may hlep it blend in a bit, but it really doesn't get rid of it. If it really bothers you, and I'm sure it must, my scratches bother me, and the installers scratched it, then contact the retailer and ask them to replace it and send out a crew that's more careful with your appliance. That's the only way I know of to rid yourself of the scratch.
There are solutions for minimizing the appearance for these scratches. I, however, believe the best course of action is to simply accept and embrace these scratches. This is similar to those Le Cresuset stains. It is simply better to accept these minors stains instead of trying to clean them shiny white clean every time.