I, and likely most others, wouldn't call cancellation fairly easy if I need to manually send an email to do so. Fairly easy would be a 'CANCEL' button in an easy-to-find place within the account settings user interface, not hidden in some submenus with ambiguous wording like Chegg, but you and I both already know that you likely want to keep it difficult in hopes people won't go through the hassle to cancel and you can increase revenue. The only problem with that is that word gets around online. Before you know it, you end up relegated to the realm of a company like Chegg, which people absolutely hate for their shady business tactics and similar, although surprisingly slightly better, cancellation difficulty than here at Known Host. If there is some other valid reason why customers must cancel manually this way, I'm all ears.
I do agree with you on the refund, as it's my responsibility to keep tabs on what's coming out of my account, so there are no qualms there.