Talk to the NPC that holds your stuff if your house got demolished.

If he doesn't have the stuff, you might just not have placed an Miniature Aetheryte in your yard. Why not go to an Aetheryte in Ul'dah, Limsa, Gridania and select "go to ward with private estate" or whatever the line says? -> open map, look for plot with a star next to it and voila.

If that doesn't work I'd say call support.