adding more storage to iCloud
I have two Apple-accounts. One for everything to do with working with iCloud and one for the Apple Store (everything involved paying for stuff)
Usually everything is OK. When I have to pay for stuff (books, music etc) iOS/OSX comes up with a dialog with my Apple Store account so I can pay. The strange thing is that when I want to expand my storage space for iCloud, I can't switch to my AppleStore account. You simply have to pay with the iCloud-account that you want to expand. For security reasons I didn't attach any Creditcard to my iCloud account.
Fact is I can't expand my storage space.
How can I solve this without adding pay information to my iCloud account??
iPhone 4S, iOS 7.1, iCloud App Store