Caller: Overseas scammers

Indian woman saying she is from Telstra. When I said "No you're not, but anyway" she hung up on me.

I called the number back a little later and "Optus advises the number has been disconnected".

I only get overseas scammers calling my landline these days so suspect they are all scammers. Hard to convince someone you're from Telstra when you're calling from an Optus line and I have no phones with Telstra.