Your only option is to try to find out who owns the address they were sent to and ask them to send the BTC back.
He knows that, it's cloudmining.website, a some would say dubious cloud mining operation.
They don't disagree that they have the coin and say that management will make a decision in the next 24 hours.
http://forum.cloudmining.website/viewtopic.php?f=3&t=42&p=187#p187