when I questioned them about why they need all my personal details and how do I know you are not a scam and to prove to me they are not a scam- they hung up on me, then blocked my number.

They claim they are from westpac and want to talk to you about product they send out.They ask your full name and hang up when you ask for more details about who they are.
Some kiwi chick answers and hangs up on you

first time I answered he said he was from Westpac but I said I was too busy
then this same number kept calling every day for the past week but I did not answer

I have also had calls from this number at least twice daily and call back and only get music. I used Lisa's idea above and saved it in my phone and blocked it so I can't get calls from them.

pestered by this caller up to three times a day,

I have received from this number too seems like scam they don't leave a message or pick up the call it just goes straight to music I have blocked the number.

I too have
Been pestered by this
Number whilst ive been out when you
Call the number it goes straight to music!!!!!! - SCAM!!

I rang back this morning only got music

they ring daily both mobile and landline when you ring back you get music only