it's often way faster to google the emails of their executives. you're ideally looking for VP of Customer Service.

you can BOTH lose

make sure to put 'if you want people contacting you through appropriate channels, don't use them as a data-harvesting opportunity' as the signoff.

you may need to use the advanced technique of " resume" to get their previous position's email, which will have an out-of-office message pointing you to the address they moved to. This may require multiple hops.

just because they want to make your life miserable for a quick buck, even if they don't bother to realize it, doesn't mean you can't return the favor just a little bit.

I choose to be as kind as possible in the world. There is no kindness reserved, no possible kindness deserved, for 'you must sign up for an account with your email, which we will send things to and also sell, to contact our chatbot'.

I am like a water buffalo, when I have been morally injured I will persistence hunt you to the end of the continent unless one of us dies.