Just lost $850 on a Home Inspection. What can I do?

I was in the process of purchasing a home and had a home inspection done. On the papers that I and the seller signed it said that there were no known problems with the home. So we have an inspection done and there is problems with EVERYTHING!!! The septic system had problems, along with the water, mold in the attic, and the radon air level was 38000!! (not a typo!) Is there anything I can do to get any of my money back?