I also received a message regarding Oakley Sunglasses and a http://tinyurl.com link. Blocked caller in case of any more calls.

It would be almost impossible to find where they got the number from. Almost all online purchases require a phone number.

I've never used my other mobile's phone number to sign up online, call or message anyone. That number has never been given out to anyone. I can only conclude that Telstra is giving / selling our numbers to others. Got a text message with a link to purchase Oakley Sunglasses. I didn't click on the link as it could be a phishing scam or open keylogging ware etc.. The phone is only used to access Mobile Foxtel when my disabled son and I have long medical appointments. No apps downloaded onto this phone. Nothing comes up when I do a search on this number.