This also happened to me - obviously the case of can't say no lol. If you signed up to the royal flying doctors service, they will call to confirm your donation and I think give you a few T&C's about what you're getting into.

Don't know who this number belongs to but I assume it's spam as they've rung me about 5-6 times since last night. I foolishly signed up to give money to the Royal Flying Doctors Service and that's when the calls started.

I called back number 0480 027 260 was put on hold music but no one answered the call.