Chasing for money the same as others, threatening. It is legally in the US considered to be harassing. The easiest way, unfortunately, is to cancel your card and block them everywhere in your email inbox. And the next thing is to forget about them.. :) Yeah, it is a hassle but I actually had the same issue with Google GSuite (who would think right?) No sweat guys! Save your nerves! :) Any court in the civilised country will consider that as an offensive clause and will cancel it as a violation of your rights. Are there any lawyers in here who can advise on that from the professional standpoint? Also, to ppl who are considering the service, one word: RUN (subjective personal opinion)! :)