Can not buy
Icanot buy
iPhone 5, iOS 6.1
Icanot buy
iPhone 5, iOS 6.1
Any more information about the problem e.g. what can't you buy, do you get any error messages, ... ?
If you are getting a message to contact iTunes support then you can do so via this page and ask them why the message is appearing (these are user-to-user forums) : http://www.apple.com/support/itunes/contact/ - click on Contact iTunes Store Support on the right-hand side of the page
Can not buy