Seems legitimate.
They rang me as soon as I accidentally tried to make a second payment online that took me over my daily limit. They advised me to contact my bank & didnt want any more details from me

Caller: Fraud Prevention

My card was declined for a purchase. An hour later this number called me to say they had blocked the transaction and asked whether the transaction was legitimate or fraud. The number is legitimate.

I claled back number (02) 8299 9534 reached voice mail but did not say for what company.

This is a legitimate number. As above, they do transaction checks for Credit Institutions.
If you're not sure ring your bank's card info line.

I called back number (02) 8299 9534 reached voice mail but did not say for what company.

Caller: FraudBureau

SMS SPAM claiming from FraudBureau