I’m sorry this has happened to you. If you follow this  announcement you will find that your case is the 3-rd one reported. CryptoMixer.io over years earns its reputation and loyal customers. We spent a lot of efforts developing it. We have no intention to ruin it. We understand that our work is built on trust. It is much more important for us to keep a client than to get a one-time benefit.

If you say that you have managed to check your browser history, than more likely you have used a clearnet browser to access our website. There are numerous schemes that scammers can use, besides phishing-websites. I.e. https-spoofing described here. That is why we always recommend to validate the Letter of Guarantee. Don't neglect this if you mix the reasonable amount. Scammers are evolving. Be careful