Lesson learned but what now?
This is my screenshot proving that I performed a tx. I wasn't on phishing sire for sure - that much I do know
Here is the screen shot of it
https://m.imgur.com/a/yeh7m50You can even see the screen has confirmed the output
What to do now?
BestMixer hasn't logged in here since April 9th, so I don't know if we can expect an answer from them here.
Keep trying to talk to them through their support system. That's probably all you can do. Without a Letter of Guarantee, I can't be definitely sure if what you are saying is true to neg-tag them. If they don't answer you or don't come here to defend themselves, I may tag them (as a possible warning for other users) until they do.