Look for another breaker
Hard to believe there isn't a breaker for the thruster, which would have shut it off. Have a good look around and see what other breakers are installed. Try switching any you find off to see if they're for the thruster. Beneteau installs seperate breakers away from the main panel for the anchor windlass and I wouldn't be surprised they do the same for the thruster. They're usually in the aft cabin on the forward face of the bunk next to the battery switches. Some others can be found in the forward cabin as well. I'd start forward first. Also check your manual or call the local dealer or even the factory, but unless someone did a poor job on the installation there should be one. Some were factory installed, others by dealers or local shops. If there isn't one then install one yourself or have it done so you don't run into the problem again. I'd also see if I could figure out what caused it to stick in the first place. Perhaps a bad switch at the helm? Or a sticky relay in the unit itself? Good luck.Mike