If there are transactions using GoPay that are not known to your Apple Store, please check your History menu in the GoPay section and select GoPay as the payment filter. Every transaction you make using GoPay will be stored neatly on the page. 

You can also do the following things:

1. View transaction history by going to the iPhone Settings > Apple ID > Media & Purchases > View Account > Purchase History
2. Check the transaction by following steps at https://apple.com/bill
3. Confirm with family, friends, or closest relatives to find out if there are transactions without your knowledge that are connected to other devices
4. Confirm to the Apple Store through this link https://apple.co/3zCUtFh
5. To request a refund from Apple, visit this link https://support.apple.com/en-u...
6. To cancel a subscription from Apple, visit this link https://support.apple.com/id-i...

Hope this information helps you