Caller: Some sort of product testing

They just keep calling. Even though i tell the person this is 6 times i am not intrested to do your product testing .... they just keep ringing and asking a permission to send me a text message.
Last time i try to ring them back i have got message from telstra, number you have called is not connected check the number and try again .. .
After that i have phone call from this number again and I asked the lady where you calling from she said from Sydney . I said to her you are not calling from sydney because , i rang you back and your number is not connected ... then i hang up ....
Very annoying they got another number starts with (02) 3302 6899

no message left. Will block.

They just keep ringing me up and leave no messages ..

non stop spammer