The premise is you've signed up for a service that advertises zero-risk cancellation after a trial period. On attempting to cancel - by stopping use of the ser

The premise is you've signed up for a service that advertises zero-risk cancellation after a trial period. On attempting to cancel - by stopping use of the service, by trying to cancel on the website, by emailing them, by calling them during your work hours and sitting on hold for an hour of my time that's worth more than the entire value I got out of the service, and recording the 2 minute interaction with the 'customer service' agent, by calling again the next month after they still didn't cancel, by escalating to a supervisor and recording that interaction, and getting billed again - it often turns out that it's impossible for mere mortals to cancel. In that case, cancelling by changing your credit card number is reasonable. Yes, there's a small chance they'll chase you to collections and attempt to harm your credit score if you do actually owe something (if they shipped you something physical, for example), but often they just drop it.