Why not do both? Give the credit and send the email.
What would make their customer service just a little bit better? Being able to report a problem that's NOT on their list.
I've had a few movies I watched that were at the wrong aspect ratio for the TV, and I couldn't fix it with my tv "zoom" menu. The frustrating thing is there's no way to report it (though I guess you could drop it in the "picture was unwatchable or blurry" bucket)
We should also give credit to Netflix and those who at least choose to notify their members. It is almost like the "honor system."