I bought a movie from itunes, and when i try to play it on my iphone it says can't play?

Plizz help or how can i report an issue to itunes

Not all iTunes video can be transferred to iPhone, If the video resolution or video bit rate beyond iPhone limitation, you can't upload them to iPhone. For example, some iTunes purchased movie are High definition movie, the resolution is too high to play on iPhone, but you can highlight the problem video in iTunes and choose Create iPod or iPhone version from the Advanced drop down menu. When the conversion process has completed, sync the new version to your iPhone. Fore more info, here is a guide about how to convert video to iPod/iPhone. Hope it helps. Contact me if you need further assistance.