You have your store set up fine but there must be another plugin you have installed adding that information to your head elements. In your source code I see this:
<meta property="og:title" content="- Vintage Shopper"/>
That appears above your Datafeedr meta tags which are correct:
<meta property="og:title" content="SAMPLE SALE - Maggie Sottero Spring 2013 - Alaina Ivory Satin & Embellished Lace Wedding Dress"/>
Can you disable whatever plugin is also adding that information? At least disable it on the "Store" page.