Best Buy purchase, Warranty Issues, Dell Laptop

I purchased an open box Dell Laptop from bestbuy. The laptop worked fine for a few months and then gave me a warning that "the battery has experienced a permanently failure and needs to be replaced". I contacted Dell support and asked for help (since the laptop was still under warranty). I was asked to verify the person who was the original owner of the laptop (the person who bought the laptop before me, registered it and then returned it back to bestbuy). Now, how am I suppose to get that information.. The Customer rep said "its easy, Just walk into bestbuy and ask them the info". I didn't know  if i should cry or laugh. Why would bestbuy give me the information of the previous owner. It looks like Dell doesnt want to honor the warranty anymore even though i am the legal owner of the laptop. Take Home Lesson - Never Buy an open box Dell Laptop from Best Buy.