I have a £44.99 charge on my bill, however, i am unable to locate or find any purchases i made, nor any subscriptions.

As already suggested, contact Apple or, better, contact iTunes Store Support team using this link:--> iTunes Store & App Store – Get support for various issues

choosing: your country, then Apple ID, then iTunes & App Store. If your problem is not among the options shown there, tap/click on the option “the topic is not listed” and describe your issue.

Regards

Giulio

Scam attempt? Was that amount of money already withdrawn on your bank statement? See this support article:--> Recognize and avoid phishing messages, phony support calls, and other scams - Apple Support

For any further question, read this support article:--> Subscriptions and Billing – Official Apple Support

and/or contact Apple Support directly, using this link:-> Get Support

Regards

Giulio