The important part described in the first article that FoxFifth links is "view your purchase history." I believe you have already done that.
If Apple does NOT show a record of the purchases, then it is likely that some scammer has gained access to your credit card number or bank account ID and is pretending to be Apple. It is a common scam and happened to us.
If that is the case, Apple cannot fix it but your card issuer can. When we had spurious charges purported to be from another major US retailer, our card issuer's customer service had the charges identified as bogus, forgave the debt, and issued my wife a new card number, all within just over 24 hours. They also verified that the retailer shown had nothing to do with the charges.
If the Apple purchase history shows the charges, then a friend or family member may have access to your credentials. Continue with instructions in the article.