iTunes keeps billing me for £2.99 every month and I don’t know why and I would like them to stop as I have requested of this before and clearly nothing has been done as I keep being charged

A question: you have an iCloud+ plan subscription?

If you have upgraded iCloud+ plan, once your request for iCloud+ plan has been activated, you should receive an invoice in your email box.

Check -> Go to -> Settings -> your name -> iCloud -> if you see 50 GB (or 200 GB or 2 TB) then you have an iCloud+ plan subscription.

If you have an iCloud+ plan subscription, you will receive a monthly bill from Apple, check your email box.

See -> iCloud+ plans and pricing -> iCloud+ plans and pricing - Apple Support

If uou want to downgrade or cancel your iCloud+ plan, see this Apple article: Downgrade or cancel your iCloud+ plan -> Downgrade or cancel your iCloud+ plan - Apple Support (PH)

• Before you downgrade or cancel your iCloud+ plan, first download or remove content that exceeds your new storage amount. To make sure that you don't lose any information, learn how to copy what you store in iCloud.

See also:

• How to downgrade or cancel your iCloud+ plan on your iPhone, iPad, or iPod touch
• How to downgrade or cancel your iCloud+ plan on your Mac
• How to downgrade or cancel your iCloud+ plan on your Windows PC
• What happens when you downgrade or cancel iCloud+