Constantly calling but if you answer there is nothing - have blocked the number

Caller: Scam

Called me three times today. Didn't leave a number. Called back, strange music and eventually foreign loud call centre, refused to address me properly then wanted to sell me a hot water system and get me my details.

Caller: Don’t no

Hung up as soon as I answered

Caller: Telemarketer - hot water system replacement

Have called numerous times and never left a message

calls me multiple times a day, answered once and they hung up immediately.

Caller: Scammer

Was a woman with Indian accent. Something about the state government with home owners loans or finance or something. I didn't let her go into her speech. She didn't say the name of a company. I just said I don't own a home and hung up.
So tired of scammers calling me every day! Even when they're not scammers but are genuine telemarketers DON'T CALL ME! I'm on the DO NOT CALL register which seems to be a waste of space. If I want to buy something I will contact them. I wont buy anything from a telemarketer even if I REALLY need it, because they are a PIA.

Call but does not leave msg......returned call voicemail just says "goodbye"

Caller: NSW Hot Water Systems

Telemarketers trying to sell hot water systems ver poor spoken English have called multiple times

SPAM - offering free hot water service upgrade from NSW government

This number rang for 29 seconds but I didn't answer as I read that 8000 calls are illicit ones.
I am surprised the number hasn't been picked up by reverse Australia.