Caller: They said Telstra but thats cap.

A lady called me saying they are from Telstra and they were trying to imply my internet activity was monitored and something was wrong but when I tried to play a long I accidentally said "yeah my internet, Telstra?" they must have got a feeling that my isp wasnt Telstra and she hung up. I have been scam called before many times usually they don't have an actual person on the other line talking to you, this time it was different and I feel this is very illegal because they seem to be pretending to be Telstra when they are not, because I have no business with Telstra so no reason they would be calling me unless its the wrong number either way I doubt telstra would make such a mistake like calling the wrong number to discuss a customers internet usage, definitely an elaborate scam. WATCH OUT!