I’ve been getting calls from this number as well, it’s a fundraising agency called 2evolve – they partner with different charities. If you email contacts @ 2evolve.com.au then someone can remove your details, I hope this helps!

Have also been receiving calls.
I regularly donate to a number of charities, Amnesty International being one of them - and they tend to call every 6 months to ask me to up my donation.
So, whilst I haven't answered the call, I imagine it is them.

I have been getting calls from them, i used to donate but i found them rather aggressive and at time annoying about donating so decided to stop over 12 mths ago and these calls have just started up in the last few weeks.

Call from Amnesty International for donation.

Regular calls no message