IPhone 4 s, when finishing apple id in i-tunes firstly , message “please contact iTunes support to complete this transaction” appears

If you haven't already done so contact iTunes Support as instructed (these are user forums, not iTunes Support) :

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

- 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

How long ago did you contact them ? If you sent the form you should have got an acknowledgement, a proper reply might take up to 48 hours