Given it is your email that is being used, that should allow for you to take over the account(s)? I'd submit a password reset, change the password, then just allow the account to live a dormant life.
That of course doesn't make it any less annoying, but it would at least stop an actor from using an account that is associated to your email.
I am still livid on a weekly basis when some strangers create an account for a service using my email address (non-maliciously, usually); I get a "verification" email; and I can only choose "YES, Please verify", or ignore at my peril.
From tiny little mom-and-pop shops, to FAANG giants, nobody is giving me the opportunity to say "NO that's NOT me!". And though it's a "verification" email, typically account is usable and vast majority of functionality is allowed even without verification. So I get to vicariously and angrily "enjoy" the follow-up emails and updates while the users gamble, purchase, sell, review, invest, write, game et cetera using my email address.
Boo to this, I tell ya, boo!