We're sorry to see you go, do submit to us any feedback that could have made things better. We'll continue to improve ourselves with it.
Meanwhile, these steps should help you:
To get a refund or cancel an existing subscription
1. Sign in to your Microsoft Account that you purchased us with.
2. From the top menu bar, select Payment & billing > Order history (https://account.microsoft.com/billing/orders)
3. Navigate to our app you want to have refunded, and select 'Request a refund.'
Refunds depend on the Microsoft Store's policies and we can't facilitate refunds ourselves due to billing and security reasons.
For more information, check out Microsoft's solution here: https://support.microsoft.com/en-au/help/10558/microsoft-store-returning-items-bought-for-exchange-refund