See your purchase history for the App Store or iTunes Store https://support.apple.com/en-us/HT204088 to see if the subscription is shown. If you have a problem with a subscription (e.g., as in your case, your can't cancel one) or a purchase, see Subscriptions and Purchases https://support.apple.com/en-euro/billing. If you think you may be able to get a refund, then use the request a refund link. It will take you to Request a refund for apps or content that you bought from Apple https://support.apple.com/en-euro/HT204084
See How long refunds from the App Store or other Apple services take https://support.apple.com/en-us/HT210904
You also can get Apple telephone support for help in solving your problem using this link https://getsupport.apple.com/?caller=kbase&PGF=PGF63005&category_id=SC0245&symptom_id=23362 Be patient; sometimes you can't get immediate telephone support.
And here is how to contact iTunes worldwide support via text or chat using this link https://support.apple.com/choose-country-region/itunes After choosing your country, see the heading Tell us how we can help