Caller: Unknown

Calls from (02) 5639 6357 have been made to my mobile number, numerous times over the last several days. They are persistently annoying. I blocked the first number but then the callers use the following numbers (02) 5854 5189; (02) 5639 6598; and (02) 5945 7874. I have tried to call all of these numbers from an unlisted private phone (so they didn't validate my mobile), and each of these numbers are "cannot be connected". So this is obviously a scam.

Caller claims to be from Telstra and advising you have an Internet problem.
Number is spoofed as dialling back indicates number not connected.

Also get similar calls from (02) 5639 4389

Calls from this number and also (02) 5639 3489 are made to our landline two and three times a day. Nuisance.

I have no idea who this is so i didn't answer the phone and it called back a three more times

Caller: I didn't answer so I don't know.

They have called my telephone a couple of times so in order not to validate my telephone number to them, I called back using Skype. It came up as as invalid telephone number so perhaps it's a scammer calling from overseas?