What would you do if a 150 lb unleashed American Bulldog attacked your leashed 55 lb Mutt on a walk?

It was an unprovoked attack. The Bulldog has the jaws of an alligator and the hold of a python, according to a website. His owner could not get him off. My dog had to undergo 5 hrs of surgery, as the vet had to insert a drain in her brain. The owner of the attack dog has refused to help with the vet fees. She claims that she does not have a job and stated that my dog bit hers too. Her dog was not hurt, as it had its jaws clasped around my dog's head. What good will it do to call Animal Control and to place an incident report with the police department. I am concerned that this dog will attack another dog or even a baby or another human. Has anyone had any experience with a dog attack?