So you used a bridge to move ETH (or what was supposed to be ETH) into Bitshares, and then the bridge burned down. Yeah that sucks. While I don't think he went out and bought a yacht with your $275, its possible they kept a hundred grand or so in coins. Sounds like most of what was lost was MAID.

The OpenLedger guy is pretty active on Twitter. You can ask him about what do there. I recommend not accusing him of scamming or anything at first as he'll be less inclined to help you.

Out of curiosity, what were you planning on buying at Bitshares? I notice its undergoing a pump, but other than that I can't imagine anything new is happening over there.