Clash of Clans purchase
I just tried to buy the Builder Pack on clash of clans, put in my apple id info, then it said "Your Purchase Could Not Be Completed for assistance, contact iTunes Support at www.apple.com/support/ww/"
iPhone 6 Plus, iOS 12
Question marked as
I would suggest calling in to Apple Support - https://support.apple.com/en-us/HT201232
Technical support can get you over to iTunes Support if the IVR doesn't immediately route you there.