I had the same happen with a AU insurance company that also made it hard to reach them.
I sent an email to their regulator that this company keeps sending me confidential information about one of their clients. It took one day until I received an email from the company informing me that they've corrected the mistake and I shall no longer receive any emails, and it worked, I haven't received a single one since.
If I made a mistake while entering data, I'd be happy if someone told me they receive emails from me that they probably shouldn't be getting, so I do the same when it's not obvious spam/scam.
same. although, if it's a reservation you're being sent, you can cancel it to let the person know they're using the wrong email (plausible deniability because you don't recognize it, yet are getting a reservation)
I sent an email to their regulator that this company keeps sending me confidential information about one of their clients. It took one day until I received an email from the company informing me that they've corrected the mistake and I shall no longer receive any emails, and it worked, I haven't received a single one since.