You can cancel the service at any time by going back to the page you subscribed on and by clicking ‘cancel integration’. 

1. Go to your organisation page by clicking the building icon or organisation name in the top right of the menu bar
2. Open organisation settings > premium services > integrations > cancel integration

Note that if this is your only paid service, you will be billed for the remainder of the contract term (12 months) if you have not already been billed up until this point.