Make sure you’re making your voice heard on your reviews of the game, be they on steam or whatever storefront you bought it on.
If you’re in the US, file a complaint with the federal trade commission: ReportFraud.ftc.gov
Submit a report/complaint to the Swedish Consumer Agency:
This company sold this product based on public statements made that they would include a solo mode playable with bots. I, like many of you, bought the game based on this promise, since it exists in Vermintide 2 and was quite fun. Once they made their sales, and continue to make their sales, they removed solo mode from their plans.
This is called a bait and switch. It’s unethical, it’s wrong, and they will never address the issue without people making their voices heard. They’re clearly not listening here on their forums.