Update : After reading the page
http://www.bitmixcoin.io/faq.php I'm pretty sure about it either you copied content from the bitmixer or you are new owner of the service sold by previous owner to you or the service of bitmixer relaunched with a new name.
BitMixer made a statement on this before:
2. We do not sell the domain name nor our software nor methods we used for mixing.
Which leaves just one option: they copied the content. I'm against plagiarism
and fight it where I can. Plagiarism also deserves a perm ban on Bitcointalk.
The page
http://bitmixcoin.io/why.php is a piece of art:

While copy/pasting verbatim, they didn't even bother to change the name BitMixer to their own. Let me
archive that.