If you're sure that those charges come from Apple (check your bank statement very carefully, ignoring scam messages that might be addressed to your iPhone), start reading this support page:--> Subscriptions and Billing – Official Apple Support, and check each of the first 3-4 sections.
If you cannot find the information you were looking for, please contact iTunes Store Support Team directly and explain your problem, using this specific link:--> https://getsupport.apple.com/?caller=ikb&PGF=PGF51002&category_id=SC0060&symptom_id=21084
(if you get no help, look at the bottom of the link, where you can contact them using "chat" or "phone" options).
Regards
Giulio