You can always cancel any Direct Debits in the Monese app but please be aware that cancelling direct debits is a 3 day process so you need to cancel it more than 3 days in advance to avoid the next payment.
Cancelling direct debits on iOS
Navigate to the Account menu, tap on Direct Debits and choose the one you want to cancel.
Cancelling direct debits on Android
Open the app menu, tap on Direct Debits and choose the one you want to cancel.