I called back number (03) 9778 7863 rang once then goes to busy tone.

Caller: Claim to be from the technical dept of Telstra

They called me 4 times in the one day. Last time I told them to stop hassling me as I knew it was a scam. I think they call from overseas and imitate an Australian phone number.

Caller: Scam

Came amidst a barrage of calls on the same day from various source numbers. Some obviously bogus like 0658235, some blocked and two from this number. Also one from (03) 5625 1422, which doesn't list as a scam number and could be a genuine wrong number, but a bit of a coincidence, as my landline is only ever called by marketeers and scammers.

Claims to be telstra technical dept. Scammers.

Male Indian voice advising me my router was sending bad messages. Told him to get a proper job.

Either no one there or they hang up. Marketers.