You can change your Spotify payment settings by going to your "Account" menu on the Spotify website.

Canceling your Spotify Premium subscription is a straightforward process, but it requires specific steps that must be completed through the Spotify website. Unlike many other subscription services, ...

For the occasional listener, Spotify's default app settings might work just fine. However, if you're streaming music every hour of every day, you probably want more control over how the app behaves.