We are fellow users and these are user forums, we won't know why. If you haven't already done so do as the message is telling you to do and contact iTunes Support :
- click on your country's flag (the country where you are, and which is therefore the country on your account)
- 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