I Lost My STEEM!

So I'm relatively new to cryptocurrencies. I've done my research and I hold some STEEM, as one of my currencies.

I tried to transfer my STEEM from Poloniex - to - Bittrex , and I used the wrong address....

Is there a way of recovering the STEEM? I sent it to an long rendom address, and am hoping since the STEEM is sent by username, that they can recover it, if the username hasn't been taken?

Thanks!