Already saw that picture. But it doesn't say the key words in BTC.

If the promo material says that then since admin told you that they are denominating everything in USD then that is clear evidence for shady behavior.

Without these words, the site could simply tell people that "USD lossback was implied the whole time it's just that people didn't bother to understand it".

Also if they didn't pay you any loss then since they removed the promo banner after you complained that would warrant a flag.

Since you used the type 2 "casual or implied agreement" flag I will reluctantly support your flag.

Note that had you made Type 3 "written contract violation" flag, I could not support it since bonus isn't even mentioned on their Terms of Service page (the promotion banner you linked in this post is not a legal TOS agreement because it's not in the Terms page).