Welcome, I am Cory.
I am sorry you have bid the wrong amount.
Please make sure you are logged in your account, then go to the bid retraction form. - http://offer.ebay.com/ws/eBayISAPI.dll?RetractBidShow
Once you submit this, it should be removed.
If you have any questions, please reply and I will assist you.
Please do not forget to rate my answer 3 stars or higher above for helping you today.