Although there is no better way to get feedback from customers than to interview them, providing a one question Net Promoter Score (NPS) survey with an optional text box for additional feedback within your app, software, website, or in an email to members provides users a quick and relatively pain-free way to communicate with you about the service. Check out promoter.io for a service that has worked well for us.
Not only will the NPS data inform your executives, but the optional text box for feedback may result in rich user stories. Your NPS survey should be reviewed by someone regularly and that person/team should respond to users who provide feedback, especially negative feedback.
A cancellation survey is another good way to get feedback from users. When a member cancels a service, ask for feedback through a short survey. Although most of it may be negative, you'll learn a great deal about what doesn't work for your users.