Some one put Lava in my house, right where I had my home warp set.

contact a mod ingame to have fixed.

I already banned the griefer earlier. What you have claimed as your house happens to be next to an old city that lost it's protections at some point and apparently the griefer thought your home was "fair game" as well. Which, if you'd like to keep your home, I'd highly suggest following the accepted procedure for claiming abandoned lands. Take a couple screenshots of the land (including structures) and make a post on the forum asking for permission to take over it. Alternatively, you may want to find a more wilderness located area to make your home or buy a lot in a city.