Overcharged

The blue text in the previous post is a link to more information:

Request a refund for apps or content that you bought from Apple - Apple Support

See also:

If you see "apple.com/bill" or an unfamiliar charge on your statement - Apple Support

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Did you actually see this charge on your card/bank statement? Or did you just get an email about it? If it was an email, it may be a phishing scam.

If it was an actual charge, start here:

Request a refund for apps or content that you bought from Apple - Apple Support

I would suggest contacting Apple Support to ask them what the charge is for. Ensure that you have all necessary documention to hand if you have to discuss the matter.

Then follow the directions in the link I provided.