This is really simple.
1. You have never noticed this before and that you now are shows you know your vehicle's condition.
2. Because you know your vehicle's condition you bring it to someone you feel you can trust, that dealership.
3. There was no noticeable damage before.
4. There's no noted damage prior to this repair, ever.
5. It's there now.
6. Tell the dealership to make it right. They screwed up, own up to it and be right.
7. I dunno about the other person who replied above but I'm a retired Master-Tech and a current Parts-Master and I've seen this more than once in the 25 years I've been in the industry.
Each time this was because of what we both have replied with here, bad mounting and tightening of the wheel on the spin balancer, or in one case, letting the wheel slam onto the ground. The tire didn't protect it when the wheel got damaged on the shop floor because it was dropped down from up high to flat.
Yeah, they're buying you wheels. Plain and simple. Show me any small claim court that won't find for you and I'll pay your legal fees. They screwed up. Feel free to go and get a second opinion after bringing it to them and showing it to them and asking them to inspect the wheels right now because the cracks even on this screen look fresh and aren't filled with road and brake dirt meaning the damage is new. Hell even an insurance agent can tell if you want to really wind this up with them. Insist on the wheels being replaced. Hand them a letter saying that. If they balk goto your insurer and initiate a vandalism claim. Factory rims run $350-$597. Midline that price and it's $1600 that your insurer can pursue after squaring away with you if they like.
*Sorry you had this happen, I had a similar deal and did exactly the above and when it was said and done my insurance paid out for me to get it fixed elsewhere and then went after the shop for the reimbursement. All because a tech (that was fired shortly after the incident) got lazy and shortcutted a repair and damaged a major safety item.