I have been charged £28.49 for wowpaper daily live wallpaper that I did not order, how do I get my money back

For payment/billing related questions remember on this forum you are not speaking to Apple but to members of the public much like you. If you are querying an authorised payment or want a refund you will need to speak to Apple directly.

These links may also be useful.

Subscriptions and Billing - Apple Support

View, change, or cancel your subscriptions - Apple Support

Get help with subscriptions not billed through Apple - Apple Support

Identifying legitimate emails from the iTunes Store - Apple Support

Avoid phishing emails, fake 'virus' alerts, phony support calls, and other scams - Apple Support

Get help with an item purchased from the App Store, iTunes Store, or iBooks Store - Apple Support

Contact Apple Support

Reminder: For payment/billing related questions remember on this forum you are not speaking to Apple but to members of the public much like you. If you are querying an authorised payment or want a refund you will need to speak to Apple directly.

If the only indication of the charges is from an email or text, be aware that it may be a phishing attempt to get you to log in to a site that appears to be Apple and divulge your password or credit card information. Avoid phishing emails, fake 'virus' alerts, phony support calls, and other scams - Apple Support

You can use the following instructions to determine if it is a real charge, what it is for, and to report a problem: Get help with an item purchased from the App Store, iTunes Store, or iBooks Store - Apple Support

Also see: If you see 'itunes.com/bill' or an unfamiliar charge on your bank, credit card, or debit statement - Apple Support