Australia Reverse Phone Lookup

I received a call from this number when I ansered there was lots of back ground noise before a male voice says he is from the Comm Bank. I hanged up and dialled the number which answers with Commonwealth bank and I was imediately put on hold with music no options which is very strange, waited approx 10 mins and gave up. I want to know why they are ringing me and how did they get my mobile no!

I received a call from this number claiming that they were the commonwealth bank and asking for details. It occured to me that this seemed like a hoax so i did not provide them with any details. When you call back it has the computerized voice saying this is the commonwealth bank then plays hold music for a long time until you hang up. Its very suss and Im pretty sure its someone trying to committ bank fraud.