If your review was unapproved, it means it was rejected.  Some of the reasons Ive heard are: not enough juicy details, too much personal information about you or the provider, inconsistent with previous reviews, etc.

You can submit a problem report to find out why it was rejected, and then edit and resubmit if you want to.

First, read the review guidelines.

You probably either wrote something in violation of the guidelines or are a new TER member with limited history and they didn't post it based on that.

If I remember correctly, there is a button/icon to the right of the denial... if you click it the reason will be displayed.