Certainly if you can get the contractor back, and have them do a good job, that would be best. Perhaps a well-placed call to the Better Business Bureau if they don't want to fix their mistake will prompt them. I've had okay results using that avenue. Failing that, you'll probably end up renting some appropriate equipment if you want to do it yourself. Tiller, boxgrader, and roller all come to mind as a start. It's enough to make you lose more faith in your fellow man when people don't do what they say they're going to do.