If you're referring to an iCloud storage upgrade, click here and downgrade to the free 5GB; otherwise, click here and follow the instructions. If you don't have an unit where you can, use this link to contact the iTunes Store staff.
If you're referring to an iCloud storage upgrade, click here and downgrade to the free 5GB; otherwise, click here and follow the instructions. If you don't have an unit where you can, use this link to contact the iTunes Store staff.