Have you considered passing it on to a family member or friend and telling them the full story? That way if they get back to you the monitor can be returned. I had a similar problem when I got a used phone sold as new. The company in question never asked anything of us to return it and we asked what to do but nothing was said. When the delivery man with the new phone arrived he refused to take the other one. I sold it to a friend under the agreement that they may have to give it back and I would refund them if it had to go back.