I called back number (02) 8897 8986 reached voice mail but did not say from what company.

Wasn't very happy to answer the number they did hang up. Aggressive telemarketer ?

Caller was trying to sell advertising boards in Brisbane promising a 15% return and a guarranty. No Bank Guarranty, just theirs, whoever they are. I buy the advertising boards, hey get the advertisers to sign up and then I get the income. Even if this isn't dodgy, there are too many spots for this to fall over. Even tough I have told them I am not interested they keep pestering me, therefore it is a scam. If this was genuine they wouldn't need to pester people they don't know.