How do I get them to stop calling?

Received 2 calls from "BC Pub Sectors" a.k.a. 1-(604) 482-3100 today.  Lady with thick accent stated that she had a message for "Mr. _____".  I asked what the message was in regards to.  "Children's Safety books".  No thank you, please remove us from your list.

This number left a 3 min message that all you hear is the clicking of a keyboard in the back ground.

This # keeps calling even though i told them on the 1st call that i was not interested. i just pick up the receiver and put it down. they don't get the hint. i am on the do not call list also.

Repeated calls from lady speaking very very poor English. Could not understand her.

For a few years now I have been called by this charity. I have donated twice and the last time I got an invoice/receipt that stated in fine print that it was not a registered charity so there'd be no tax receipt or something like that. I was called in December and told that now they'd only be calling every two years...would I like to increase my donation to, presumably, cover the two years? They suggested an amount that was about 4 times more than I was willing to donate (can't remember the exact amount). I said I couldn't afford what they suggested. The woman hesitated but said whatever I could donate would be fine. I got the invoice/donation sheet in the mail that had the amount of $175 or something like that in the "please pay" box. I was so annoyed I didn't send any donation. I've been receiving calls every single day for weeks that never leave a message. I would like to know whether this is a legitimate charity.