Kaspersky. Back when the russians started getting weird with things, and kaspersky… got dubious… I canceled my subscription and switched to a different AV. when it was about to expire, they sent a ‘we’ll automatically renew’. So I tried to log in- my credentials were invalid- I use a PW manager, so no. It wasn’t a bad password-
the password reset option wouldn’t work (literally wouldn’t send the validation link.)
Called their CS who told me that subscriptions were handled by a 3rd party in the US- Digital River.
Digital river said I should cancel it on their website.
got DR and Kaspersky’s CS on the same phone call. they finally complied and canceled the subscription.
A year later… “Your subsctiption will automatically renew!”

called them again. sent a letter. thought that was that until I saw they billed me anyhow.
tried to call them. they were giving me the run around.

Called the bank. to report fraud.
They were useless until I told them my next call would be FBI’s financial crimes people. Suddenly, that charge back became super easy.