So sorry to hear about this. It’s infuriating when someone prangs a car and doesn’t have the decency to leave their details.
As others have said, Motability will arrange a repair and it will only cost you the excess, but it will affect your no claims history if you are planning on leaving the scheme. There are, however, two other options.
1) Motability will allow you to leave the car with the damage and when you return it they won’t penalise you via Good Condition Bonus. They gave me this option but I declined as it was worse damage than you have and we’d only had the car a few months 🙄
2) You’d be surprised how a decent cutting polish can remove an awful lot of marks and scratches on paintwork. I use Autoglym Paint Renovator. It won’t get rid of deep scratches that you can feel with your finger nail, and obviously where the paint has been removed, but looking at your photos I’d bet you can get it to the point where it will be barely noticeable to anyone else (although you will know it’s there). The dent in the black section will need professional attention though and may need replacing. Smart repair specialists tend to only deal with minor dents on flat panels or areas where they can be easily filled. The black section looks beyond that, but no harm in asking them to look at it (they will ask for photos and generally say whether or not they can do it). If you are seriously thinking of leaving the scheme and want to preserve your no claims history, I’d take this approach first as you’ve nothing to lose and obviously you can use the £100 that you’d save on the excess towards any smart repair.