This is what I got when I tried to initiate their services from my computer:
-----START SIGNING BITCOIN ADDRESS-----
1BitmixerEiyyp3eTLaCpgBbhYERs48qza
-----END SIGNING BITCOIN ADDRESS-----
-----START LETTER OF GUARANTEE-----
We hereby confirm that BITMIXER.IO has generated the address 1Q9ApkJ1wagVSfNvTdS135f3rfNweDZkJQ in order to transfer incoming amount (minus fee) to the following addresses:
100% to 1N6T1QQG6tGnAMTFHwgb84ASBKoroM22bN
This service will be only available for all bitcoins received from July 22, 2015, 2:13 to July 22, 2015, 14:13 GMT with minimum amount of 0.01 BTC. Our fee is 0.7021% + 0.0005 BTC for every forward address.
This letter is digitally signed by our main account: 1BitmixerEiyyp3eTLaCpgBbhYERs48qza. Stay protected and thank you for your services.
-----END LETTER OF GUARANTEE-----
-----START DIGITAL SIGNATURE-----
HAsZXinryVgp5SFz4tUJt1dDnewYRXxKs3LpwwzDzVAhCap1qdhecSTnvwCwjPiOUpiAHu+IEWWsiKwQCTVhCmo=
-----END DIGITAL SIGNATURE-----
I was able to verify the signature, the date matches when I initiated their services and the details match what I had input into their site.
You were almost certainly on some kind of phishing, or otherwise fake site.
If you wish to contact them regarding this matter, upon visiting their site, I found a link titled "contacts" that would probably be a good place to start, the link is:
https://bitmixer.io/contacts.html that page also lists the following email address:
support@bitmixer.zendesk.comThey also have an account on the forum,
BITMIXER.IO, and you can send a PM to that account, although they are not very active on that account, likely for anonymity reasons.
edit: I also see that the address you were instructed to send to has a transaction from that address with change back to that address (eg they reused an address), it is my understanding that bitmixer.io does not reuse addresses.