Hi there and welcome
It is possible they flagged the purchase as exceeding a limit. You need to go to iTunes support for this as this is a forum and we cannot even see your details due to security and privacy reasons.
- go to http://www.apple.com/support/itunes/ww
- click on your country's flag
- click on the Contact Support at the bottom of the left-hand column
- click on Contact iTunes Store Support on the right-hand side of the page
They can then resolve this for you, its the purpose for that support channel
I am still here so if you have any problems, or would like any additional information or assistance, please do not hesitate to let me know.
And if you can take a second to rate my service before leaving by clicking one of the stars at the top of the screen then submit, that would be greatly appreciated.