The SWTC website
says hand wash warm, dry flat. You should be able to lay it flat and pin it and spritz with water, or give it a gentle bath and then pin it flat. I don't know what that person did to it to ruin it, but it sounds like maybe they didn't follow directions?
As for curling, that might be cured by blocking. Some patterns just have a tendency to curl, plus if you knit tight it might also add to the problem.