Not sure if you have paid your subscription on your iPhone? Follow these instructions:

Step 1

Tap on the Settings icon on your iPhone

Step 2

From the settings screen tap on your name

Step 3

Tap on Media and Purchases

Step 4

Tap on View Account

Step 5

 

Tap on Purchase History

Step 6

You will now see your purchase history and the last date you paid for your subscription.

If you need to request a refund, please follow these instructions here:
https://support.apple.com/en-us/HT204084