Nope. However they tried 3 times in one morning and twice on another occasion, unfortunately I was out of the country. I note your possible explanation about not leaving a message, but had I answered I assume I would be connected to a person, and would therefore be informed about the call. If so, surely they could have left some sort of message to give me a clue.
Chances are it's a robot calling, and if no-one answers, then it's possible the calling system simply drops the call rather than passing it onto an operative.
Just had a call from 08003357000
They said they were from BT, they knew the bill payers name which is worrying as she didn't sound like a normal customer advisor and she was rude and hung up when I said the person wasn't available, she said she would ring again then hung up.