I called back number (03) 9420 1400 rang 4 times then goes to busy tone.

This number is for The Melbourne Clinic in Richmond, Melbourne

They called me back eventually after I missed their first call. It was a doctors office.

this number also called me. It left a message on my voicemail which I tried to listen to but my voicemail wouldn't work and I lost the message. When I called back it said it was disconnected.

This number rang my phone, but no message was left. I re dialled it two ways - using redial last number and keying number in. Tried 5 times and got the message that it was disconnected or unavailable. How can this be when it just dialled me?
My number is (03) 9431 2353 Regards