Here is a link that tells you how to look at your Purchase History on a Mac or computer:
http://support.apple.com/kb/ht2727?viewlocale=zh_cn
If, once you have had a chance to take a look, you feel that you do have a problem with what is showing there, you can contact iTunes Support at this link:
https://expresslane.apple.com/Issues.action
Select the options that best apply to your issue. You will get a chance to provide a written description before submitting. Once you have submitted the request, iTunes Support will get back to you via email, usually within 24 hours.
Hope it gets sorted out for you!
Cheers,
GB