On Facebook, you can request to merge multiple pages together that are for the same thing. From my understanding though, the page with the more likes may be the one that is left standing and the new one deleted. I am not sure about this though so you may want to consider contacting them before proceeding with any request for them to merge it.
Here is a link from the Facebook site for a request to merge your duplicate pages from them.
Click here for the Facebook form to Merge Pages: https://www.facebook.com/help/contact/?id=238908726149664