I keep getting calls too but I can't ring the number back to find out who it is

It's some NFP charity wanting donations, but their message won't tell you who they are, just saying that NPF charities are exempt from the Do Not Call register. If you leave them a message by don't respond, If you answer when they call they hang up on you.
It's very frustrating, I get calls about 3 times a week.

I keep getting calls from it.

It's some NFP charity wanting donations, but their message won't tell you who they are, just saying that NPF charities are exempt from the Do Not Call register. If you leave them a message by don't respond, If you answer when they call they hang up on you.It's very frustrating, I get calls about 3 times a week.