It cannot recognize the difference between "Art of" and "Back to". I'm stuck in this loop and I can find no way to contact a human.

Yes it is useless. Everyone agrees it is useless, but there are ways to bypass it.

Ice_Mage found the solution of typing "other" twice when asked for topic type.

I've linked to some salient posts.

https://www.gog.com/forum/general/newsletter_discounts_only_for_specific_countries/post2
https://www.gog.com/forum/general/the_support_chatbot_is_astonishingly_stupid/post1

You can look at game's entry in the support center: Cossacks - Back To War As pointed out above, saying the issue is of type "other" twice will skip to creating a support ticket. If all else fails, you can try e-mailing support (at) gog (dot) com