I had a call from them, a man called Brian left a message asking me to call him back regarding an "important business matter" - I don't own my own business nor do I know anyone in QLD...not calling back.

I asked some questions, they are debt collectors

I think it is a debt collector, i wouldnt call back!

I have few missed calls from this number (totally unknown for me) and a message to call back the number.  I'm not really sure is it wise to call that number before further checks.