Been able to find out that the mobile number belongs to Pivotel Satellite Pty Limited. They are based in the suburb of Southport in Queensland. Same issues as above, answer the phone and noone is there.
The don't list a mobile number but a landline number of 1300 882 448.

Caller: Would not reveal company name

Told me after completing recent survey (I did not) they could help me reduce my mortgage quicker (I don’t have an mortgage) and pay less income tax. I have blocked the number.

I've received calls from this number several times in the last three weeks (early January 2023). If I don't answer, no message is left. When I answered the first time, no one spoke. Giving the benefit of the doubt to the caller, I didn't block the number. The next time they called, I answered and again no one spoke. The number is now blocked.

Someone who was talking about how I did a survey for them in the past (which I didn't) and they wanted to help me by showing me how I can use my tax to lower my mortgage.
Went along with it but they wanted to setup a meeting before giving me any information. Refused to email me anything or give me a company name before I had said meeting. Extremely dodgy. Blocked their number.