2004 Saturn Ion Windshield Wipor Issues!

Electrical problem
2004 Saturn Ion 56,000 miles

I have a 2004 Saturn Ion. One of the windshield wipers has been acting goofy; wiping all the way of the window. Today there was a huge snow and a semi plowed right by me in the fast lane covering my car with snow. I couldn't see and had to turn on the wipers ASAP. The problem is they went crazy and the driver's side wiper (the one that had been acting up) went completely past the window and stopped in midair. Almost going into the next lane. It was still connected to the car but I had to pull over immediately to put the wipers back in starting position. They wouldn't go down all the way and are still about 3 inches higher than they should be. Now the wipers won't turn on at all. What happened? If I bring this into a mechanic to fix, how much will that cost?