How many ads are you seeing? Based on what I see when I log in as my Gold Member alter ego, you should see three, which agrees with the Donations list visible by clicking on Donations in the main tool bar. One is at top of screen just below the top or main tool bar. The other two are near the bottom of screen, just above and just below the last normal item, which varies depending upon what screen you are showing.
Also, the button to click on if you want to try to stop a particular ad is the X, not the triangle. After clicking on the X, click on Report and then on Inappropriate if that is one of the four choices. That will cause the ad to disappear until you go to another screen or refresh the current screen.