Called virgin and verified it was a legitimate call. If in doubt just call the public customer service numbers and if it's legitimate you can deal with it there.

Best not to ignore the call entirely.

Scam

They called at 7PM on a Sunday night claiming to be from Citibank Australia. They said there was suspicious activity on my debit card (of which there was none, having checked on my app) and immediately asked for my mother's maiden name - this is quite obviously a scam.

Don't believe the lies they tell you, saying that they are a 24-hour phone service and that you will get redirected to the same number if you call Citibank. This number is quite obviously a home telephone number, and the text they might send you after that looks automated (saying you have suspicious activity in your account) is quite obviously from a personalised mobile number - Citibank doesn't operate like that.

Don't listen to any of the below comments saying that they are legitimate - they were probably posted by the scammers themselves, or people who have fallen for their tricks.

To the scammers - please go make a decent living.

Citibank credit card security seeking to clarify an overseas purchase. What a great service and security. Citi telemarketing often get a bad rap, but this was a pleasure.

Citibank Debt Collection Department. They call themselves the "Debt Recovery Team". They are on a 12.5% KPI on all debts recovered.

Legitimate. Citibank calling regarding suspicious card transactions. Call the Citibank customer service number on their website.

Virgin Money Australia, I believe CitiBank is their financer.

Virgin Money credit card services

Had a few calls saying suspicious activity on my card....have no idea why as I haven't activated my card yet.

Got a call from this number and a voicemail message saying there was suspicious activity on my card. I called the number back and got a message saying the number is not connected.
I rang the customer service number for my card provider and it turns out there was suspicious activity on my card. My card was cancelled and a new one issued.

called the number back and a recorded message stating the number you have called is not connected

Scam. they are not citbank do not give any details over the phone

This number called me but stopped before I answered. I immediately called the number "this number is not connected"

I called back number (02) 8027 2000 just kept on ringing no one answered the call and never got any voice mail.

Just received a call and subsequent message from this number that advised (as per others' feedback) that there was suspicious activity on my credit card. The voicemail message left a different number to call back on which always seems a bit dodgy on the surface. I ignored all numbers provided and instead called the customer service number on my card provider's website. As it turns out, the call was legitimate and someone had in fat accessed my card which has now had to be cancelled. I suspect this number is perhaps a "dial out" line only and as far as I can tell, not a scam.

(02) 8027 2000 - called and routed to a busy tone after four rings.