I get repeated calls from this number and three other very similar ones: (07) 3741 3455 (07) 3741 3450 and (07) 3741 3432). I never answer calls from unknown numbers, assuming that if the calls are legitimate, they will leave a voicemail or send an SMS. I called all these numbers from a landline and got the same voicemail saying it was a charity. They also provide an email address to opt out of these calls, which I didn't write down.

Answered, long phase and hang up