You subscription is managed by Apple. So to cancel it, you have to use their interface directly or via your device:
In the app, click on
- Me (at the bottom of the page)
- Parameter button (top right)
- The subscription
- Manage my subscription
You will then be redirected directly to your iTunes account with a list of your subscriptions. Click on the one concerning Petit Bambou to manage it.
Apple provides tips for managing your iTunes subscriptions: https://support.apple.com/fr-fr/HT202039
If you do not see the "Cancel subscription" button, it means that the cancellation has already been done previously.
If it is your subscription that does not appear, it means that you have not subscribed via the app or via iTunes.
In the 14 days following your purchase of a subscription (the legal duration), you can change your mind and follow the procedure above for unsubscribing.
Reimbursement of a subscription made through iTunes:
You have 14 days (after your purchase) to request your refund from Apple: go to https://getsupport.apple.com/.
- Click on Apps and Software
- Subscriptions and purchases
- View, modify and cancel your subscriptions
- You can then manage your subscription from your iTunes account or be contacted by email