Caller: Im not sure but they claimed to be from telstra

I received a call from this number who claimed to work for telstra and they where trying to inform me that someone was hacking my internet and wanted to know the amount of people connected to the internet. 1st of all I'm not the head administrator/my name isn't on the internet bills let alone am I the one who pays for them. My gut tells me this is a scam just for that simple reason and for them to call me only proves they don't know that.