That depends.  If the OP is willing to spend more going after bitmixer.io, and if the jurisdiction of their owners (Norway?) is sufficiently friendly, he may be able to force their hand in the courts.  I'd start here:

Domain : bitmixer.io
Status : Live
Expiry : 2016-09-20

NS 1   : edna.ns.cloudflare.com
NS 2   : jake.ns.cloudflare.com

Owner  : Alex Bitshe
Owner  : Bitmixer
Owner  : Pb 1034 Sentrum
Owner  : Oslo
Owner  : NO

Then maybe hire a private investigator to track down the owner(s), and a lawyer from Norway (or wherever they turn out to be) in order to see if your case is viable.  You should also have the lawyer insure that they are following all of the laws of the jurisdiction in which they are based (which seems unlikely for most Western jurisdictions).  If not, you may be able to extract some satisfaction by having your lawyer notify the authorities in their country that they are operating outside of the law and providing them with the contact information turned up by your private investigator.

Good luck.  If enough people put pressure on companies like these to catch up to the rest of the world in customer service they will either change their ways or be forced out of business.  Either outcome would be good for Bitcoin.