I called back number (03) 9977 7510 reached voice mail for a charity company but did not say the name.

If you ring that number you will get a recorded message message to say they are ringing on behalf of "a charity" and if you would no longer like to receive contact then email "callingenquiries @ prodophone.com". This is fake. There is no such domain registered. The previous comment from another user above about callingequiries @ prodo.com is wrong. "prodo.com" is a web development company and nothing to do with this caller. I would suggest just blocking all calls from this number on your phone.

Caller: A charity

Opt out through emailing: Callingenquires @ prodo.com?
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When you call back it is just a voicemail.