This will help with subscription issues.
The first thing to try is double touch the home button on the device and reboot the device.
Apple tracks your subscription using your Apple ID. I have access to subscription information.
First verify your subscription using this:
If you have a current subscription, pressing Restore or Subscribe will active the subscription with no extra charge. If Restore doesn't do fix it, hit Subscribe.
If you have in app purchases restrictions turned on this can block the subscription.
I have noticed that a bad data connection can also cause issue with the subscription. You might try on WiFi.
View last 90 days of Apple charges and or report a problem with a subscription.