If you see an error when you submit an ad, please do not click Refresh or Back and Submit again as this will result in additional ad submissions. Instead, go first to the My Ads page and verify your ad has been submitted. If it has not, click Post Ad, then Resume and you will see your unsubmitted ad listed and awaiting you to resubmit it. In this way, you will not receive multiple charges for what you intended to be a single ad submission.
I have requested our accounting department refund you for the two duplicate ads.