Please contact iTunes support to complete this transaction

Hello,I've recently bought iPhone 7 and when I tried to download a free app from App Store (8 Ball Pool) I got a message saying 'This Apple ID has never been used at iTunes store'. Then I wrote all the important data including my address,credit card number and codes,and everything else needed.Then I proceeded to continue with my purchase but I received a message saying 'Please contact iTunes support to complete this transaction'.I've tried logging out of my Apple ID on my phone and tried to do the whole thing again on my PC(filling the important data) and then return to my iPhone to complete the download,but the result stayed the same.

Also,I've already contacted iTunes support but they haven't answered on my question.

Can anybody please help me out with this?