Caller: Telstra

I just received a call from a suspicious number claiming to be from Telstra. The caller said that my internet was on a public domain and that my data could be compromised. The representative spoke poor English, which made me uneasy. When I told them I would verify the information with Telstra, they kept insisting that I confirm some details. I ended the call and am now reaching out to Telstra to understand what is going on and whether my data is at risk.