To answer your question, no you cannot force them to do anything. Either fix it yourself or hire someone who can fix it for you.
We already did try to figure out why our emails are marked as spam including external help and available support channels and do follow all known good practices.
I'm not looking for advice on how to make my email not look like spam to their systems. Please assume for the sake of the quotation that we did due diligence here.
I'm really asking if there is a precedence for someone trying to sue big company for damages caused by their refusal to not mark legit emails as spam.
This was the exact opposite of what I expected, but every other reasonable variable was controlled as much as possible.
No. Email is an altruistic delivery system per the RFC. You have no right to have your email delivered at all, let alone a right to have it marked as not spam. You should assume your email is still triggering the undesired spam label because of your configuration, content, or delivery approach and try to resolve that.