Pretty much knew it was a scam when the number came up on my phone as (02) 9099 2767 which is a scam number called earlier today, since blocked. This one actually left a voice message but it was just garbled nonsense, so duly deleted and number deleted.

Appeared to be spam regarding your “electricity bill”. Sydney number. Number blocked

Caller: Energy supply service

Offering Energy supply discounts, unfortunately won't take no for an answer, hung up on caller

Left a voicemail with just a 'hello' against a lot of background noise. Deleted after reading this site.

Unique offer, 'Great deals on electricity and gas' - SPAM

Caller: Unique Offer electrical

Selling electricity deals

Scam (02) 9099 2766 rang and left a message and they knew my name , after all the data hacks that have gone on no wonder they know your name , number :( I have blocked them