I don't normally answer calls from unknown numbers, but at the moment I am expecting a few legitimate calls from people whose numbers I won't recognise, so I decided to risk it. When I answered a man with an accent said "Hello Miss [Name], how are you?" (they got my first name correct). When I said I'm fine, and asked who it is, they hung up. They haven't called back. It did sound a little like there was call centre noise in the background.