called several times

Came up on my phone as potential fraud or scam so I didn't answer it, they didn't leave a message

Caller: Email bounced back

I have tried on 2 occassions to email and have my number removed but it has bounced back, see message below.
Delivery has failed to these recipients or groups:

calliongenquiries @ protophone.com (calliongenquiries @ protophone.com)
Your message wasn't delivered. Despite repeated attempts to deliver your message, the recipient's email system refused to accept a connection from your email system.

Contact the recipient by some other means (by phone, for example) and ask them to tell their email admin that it appears that their email system is refusing connections from your email server. Give them the error details shown below. It's likely that the recipient's email admin is the only one who can fix this problem.

For Email Admins
No connection could be made because the target computer actively refused it. This usually results from trying to connect to a service that is inactive on the remote host - that is, one with no server application running. For more information and tips to fix this issue see this article: https://go.microsoft.com/fwlink/?LinkId=389361

Caller: (02) 8366 7050

I have been getting calls from this number for weeks, the answering machine message was too quick for me to figure out the email address so I googled it and found it on this site. I emailed last night and asked to be taken off the phone list. Today I was phoned by the number (02) 9182 5055, when I answered the call it hung up immediately. I called back and it was the same answering machine and message. I will email again now asking them to not call from any number. I suspect it was because I blocked the first number. Are they making money somehow from us answering or calling back?? I have often answered but they hang up immediately.

called from this number and also a victorian number when called claims to be a charity, doubt it

Called several times. No message.

charity

Caller: (02) 8366 7050 caller unknown

Doesn't leave a message