I started getting similar emails for high valued purchases with an invoice number. I happen to have gmail and these messages are from a Sydney number (not mobile) and I managed to trace it back to a company called Magnet according to (reverseaustralia) and has Bondi recorded address. I tried to verify this by calling back and a man responded. When I asked who he was, he started jabbering that he is Paypal verification and I bought bitcoin this morning. I did not give my name and I used my home phone for this call and without even knowing my name he was able to give me this feedback!, When I asked him to explain how he can tell me what I did or did not do, he cut me off. This is definitely a SCAM but we are unable to catch these criminals, unfortunately!