I am really sorry they have taken advantage of you, and others, like this.
I resisted paying for Duolingo for various reasons, but this confirms all my suspicions.
The loss of the forums is tragic, unforgivable really, all those wonderful posts - gone!
I know it became a bit nasty at times in various ways, but that's a tech/management problem that needed to be solved, rather than throwing the baby out with the bathwater.
I should probably work on my addiction to Duo?