Q: I cannot purchase anything from itunes.  My credit card info is all correct.

use the contact Apple link at the bottom of this page, otherwise to change your payment info see this link:

Change or remove your Apple ID payment information - Apple Support

There might be other reasons for this. Contact iTunes Store support like the message instructs.

What does 'cannot purchase' mean, what happens when you try to buy something, if you are getting an error message then what does it say ?

If you are getting a message to contact iTunes Support then you will need to do so (these are user-to-user forums) :

- go to http://www.apple.com/support/itunes/ww

- click on your country's flag

- click on Contact Support towards the top right

- click on Get Help under 'Talk To Us'

Or use this form : https://www.apple.com/emea/support/itunes/contact.html

If it's a different problem ... ?