You need a zero account balance and you need to cancel all your subscriptions. If you have cancelled all subscriptions, but some haven’t expired, contact iTunes Support. You need a valid credit card issued by a bank in the country the store is in and you need a billing address in that country. If you have an account balance, either buy something more expensive and pay the balance with a credit card or contact iTunes Support and ask them to zero balance your account.
Purchases - View, change, or cancel your subscriptions.
Purchases - Subscriptions not billed through Apple
Link to contact Apple Support at the end of the article.
Purchases - the subscription that you want to cancel is not listed
Region - Change your iTunes Store, iBooks Store, or App Store country or region.
If necessary, contact iTunes Support. Follow through the screens to get a chat or telephone option.
iTunes Support – world wide
Apple Support schedule phone call
Have you tried pressing and holding the app until it wiggles and then tapping the upper left hand corner?
See the Apple Support article(s) below.
Apps - How to delete on your iPhone, iPad, and iPod touch.
Apps - Remove built-in Apple apps from the Home screen on your iOS device or Apple Watch
