Phone call from 1 (800) 616-5473

They called my work #, I didnt answer. They didnt leave a message and never called my cell phone. I think they might be calling me about my BIG loan. I have been ignoring BIG since August. Does anyone know who would be calling from this number? Last time BIG called me was yesterday. When I answered my work # they said they were returning my call, but didnt say who they were, just gave a name. Which for the life of me I cannot remember. I placed them on hold, looked at the caller ID and it was a local #. I figured it was one of my clients picked back up, said hello this is ___, she responded that she was with BIG..BLAH BLAH BLAH. I fell for it, let her talk for a few seconds and hung up. She called my cell and left a message saying I needed to call her back right away. I didnt. how I am getting calls from this number. Think its related? What do I need to do, if it is a collection agency on behalf of BIG can they do anything to me?