A subscription can be cancelled only with the service where you originally purchased it
All your data remains in your account after a subscription cancellation
Cancelling a subscription means to cancel the next renewal
iOS - Apple
Subscriptions bought on iPhone/iPad are managed in your Apple account. For more information on how to cancel an Apple subscription click here.
Android - Google Play
Subscriptions bought in the Android app are managed in your Google Play account. For more information click here.
Subscription from Billdu
Log in to the Billdu website with your email address
Navigate to Settings - Subscription
Click on the red STOP button - this cancels the payment recurrence.
Your subscription will continue till the end