Q: I don't need and want my money back

What did you purchase? AFAIK cards can't be used to buy iCloud storage. If you bought songs, movies or apps then strictly speaking all purchases are final, You could try asking iTunes support for a refund but be aware that they are under no obligation to do this.Go to https://expresslane.apple.com ; select 'All Products and Services' in the first column, 'iTunes' in the second column and then 'iTunes Store' in the third column.

If you are indeed talking about iCloud storage:

You can cancel an iCloud storage upgrade but only within 15 days of buying:

Apple have made this as difficult as possible. However two posters have managed to achieve this. Elizellen was able to use Express Lane to get a refund:

https://discussions.apple.com/message/19323996#19323996

However if you use Express Lane may find you cannot proceed without entering a hardware serial number which is still eligible for AppleCare.  julia22 managed to find a way round that by phoning them - please see this post:

https://discussions.apple.com/message/16968425#16968425

it gives the USA number - if you don't live there you will have to find an equivalent number from the 'Contact Us' link at bottom right of this page.

Poster 'CCrefund' has posted a method applicable to users in the UK: https://discussions.apple.com/message/21002309#21002309

If it is more than 15 days since you purchased the storage you cannot cancel it for a refund; you can downgrade your plan as from your next renewal date. Please see

http://help.apple.com/icloud/#mmd602084a

and expand 'Downgrade your storage for the next plan year'.