I called back number (07) 3099 0522 reached voice mail for a charity company but did not say the name.

nuisance caller

Frequent calls. As I am overseas they are in the middle of of the night. No messages left. I have blocked this number before and will do again. I have asked to be removed from a charity call list that I thought was this one. Ill8do it again (sigh).
If the charities are reading this constant cold calling has become counter-productive with me.

Answered and hung up on answer.

This company calls people who have donated to various charities in the past seeking further donations. They also cold call new prospects. Pleasant enough caller (a lady). You can have your number removed from their contact list by calling the number (a recorded message) and following the prompts.

Multiple phone calls- delay to respond to answer, hanged up on operator so didn't find out who it was

Continually calls every day (Mon - Fri) afternoon between 12:00 - 2:00, without leaving a message.

Continually calls and hangs up upon answering

Called without leaving a message.

left 2 missed calls in 5 days without leaving a voice mail