I called back number (03) 8091 8856 rang 3 times then goes to busy tone.

Number rings. No voice heard, but after a while says "Goodbye". This is a robodialler, finding out if your number answers in order to facilitate criminal activity. Block this number if you can, complain to your local politician and tell them to legislate to stop organized crime using our telephone system.

Rang twice in quick succession...didn't leave a message