Working with Google Places definitely ranks in the most frustrating things I do for our large automotive group... What you need to do is to get your old listings and your new listings to completely merge. Edit each listing (old and new, or at least one of them) so that everything is exactly identical between the 2 listings. Now you have to wait, could be a few days, could be a couple months, and when you see within your Google Places account that the amount of impressions is identical, then you can see that the listings have merged. At that point, remove the duplicate listing that you do not want to be dominant, and edit the primary listing to what you want.
