As the transaction process is handled by Google (for Android devices) and by Apple (for iOS devices), you need to contact them directly with the details.

For Apple (iOS) devices:
  • Visit Apple support
  • Enter the Contact iTunes store support > Purchases, billing and redemption
  • Select the option that best fits your request
For Google (Android) devices:
  • Visit Google Support
  • Select the Contact Us button
  • Select the option that best fits your request