My dog got attacked while on our walk last night and is injured

I was just finishing up my walk last night with Ozzy my 17 pound Australian Terrier when I spotted a couple of people with two off leash dogs in the grass off the side walk. I was almost home and I live in a condo complex so this was one of the grassy areas. There are leash laws here so nobody should have been off leash. Well out of nowhere one of the dogs which looked like possibly an American Bulldog or some kind of bulldog or pitt mix came barreling at us.

The owner of the dog actually started screaming Oh sh*t in a panicky voice like he knew this was bad. If you know this about your dog HOW CAN YOU HAVE IT OFF LEASH? I am normally calm when a dog runs up but this was different, I freaked and started yelling to get his dog but it was too late he grabbed Ozzy and was tearing into him. I was really screaming by now to get his dog off and somehow he did. Ozzy was shaken up but he looked ok and so after mumbling sorry several times the guy just walked off quickly. I did not chase him down because I was in shock but I can't believe he just walked off.

I put Ozzy down to try and walk home and he could not walk. I carried him home and he had a couple of punctures on his belly. I took him to the vet and spent several hours there while they worked on him. Now he has a tube in him and stiches with the e-collar and two different meds. He is a shell of himself and won't walk. He has not eaten any food or had any water in 24 hours. I think I need to call the vet back because they said he should eat last night.

I am just sick and have already shelled out 1k. I know what building this guy lives in but not what apartment. Should I call animal control? it is of course his word against mine, do I have any chance of getting my costs covered?

And poor Ozzy..