We're so sorry to see you go! If you've been having a problem with the app, we'd be happy to look into it and help troubleshoot.
If you'd still like a refund, you can request a refund from Apple in just a few steps:
Go to Apple's problem reports page: http://reportaproblem.apple.com/
Log in with your Apple ID username (typically your email address) and password
Tap or click "I'd like to"
Choose "Request a refund"
Choose the reason why you want a refund, then choose Next
Choose Simply Sing, then choose Submit
You can also speak directly with Apple Customer Support.