Go to Move Money on the bottom bar. Click on the ... on the top bar to the right of 'Move Money' and select Manage your payments (iOS) or Your payments (Android™). You'll then see the Direct Debit list. Click on the repeating payment you want to stop and then select cancel this payment. For a payment due the next business day, you need to cancel it before 4pm on the previous day. Business days are Monday to Friday, excluding bank holidays.