If a series you have had notifications for keeps reminding you after it has ended, or if you would just want to stop the recurring notifications you can manage them from the notifications menu.
1. Click the menu icon for "More" at the bottom of the screen
2. Select "Notifications"
3. In the list of active notifications, press to select the one you want to stop or turn off
4. On the program screen you will see the option to turn off the 'notification' completely or just the 'repeat weekly' option
5. Turn off the notification by 'unchecking' either 'notification' or 'repeat weekly' option