> What should you write exactly?

The facts.

Copies of marketing you saw, statements showing what you invested and what you were paid, e-mails and other communication from the company and a statement of loss. There are links in this thread where promises were made that turned out to be lies; I would include those as well if you saw them ex ante.

Here's a sample letter:

Dear government I'm trying to subvert, I complain about the instability of your useful, fiat currency, so I entered into a get rich quick scheme with no intention of reporting gains on my taxes. This obvious scam fell apart. Please punish them with the government system I don't believe in.

Are we blaming victims now? What’s next? It was her fault for wearing those clothes?

I think comparing getting scammed by get rich quick schemes to that is a morally reprehensible comparison.

Gravity in both situations may not be comparable but victim blaming is always reprehensible.