But a well-spoken, kind caller with all the software required to masquerade as a Spark technician helping combat a "hacker" was able to get personal information out of her last week.
On Monday she changed her phone number, bank account details and credit cards after eventually twigging to the scam.
"I know all about scams. But he had an app I could call up on my iPad and see how I had been hacked.
"He was very patient with me. He did it so well. I was helping a Spark technician out. But when he started to push me to put a code on my phone and couldn't because I had given him the wrong number - accidentally - all the lights came on.
"He got a bit rattled.
"Up until then he seemed totally kosher."
The man first rang her last Tuesday to tell her how Spark was in the process of contacting Xtra customers whose account security may have been compromised in Yahoo's massive data breach. That did happen in September.
"He was able to use that to get me to put the app on my iPad.
As well, the man, in his 40s with a soft "Middle Eastern" accent said Mrs Jane, wanted her driver's licence and passport number. He was out of luck with both of those because they were out of date.
He pushed for any kind of photo ID.
Eventually after a series of conversations over the five days he got her credit card number.
"He talked to me so nicely. He was so considerate and said sorry all the time or excuse me.
"Psychologically I think he had worked out how New Zealanders talk to each other."
Mrs Jane said she is older, with health problems and his calling, although polite for most of the time, wore her down.
"I've been really gullible. But I know about scams. He was using technology and came across as a technician. He had graphics and showed me other sites that had been hacked.
There was all this tech stuff on screen."
Mrs Jane did not lose any money. But she is amazed at how she was taken in.
Spark told her it would never contact anyone in this manner.
On its website it says scams follow a few different patterns, but the most common story is scammers claiming to be from Spark's technical team.
They often ask people to go to a webpage (such as TeamViewer) and download remote access software.
Spark said scanners can, remotely, "put a password and your computer and refuse to remove it until you pay them".
Spark said ring the company if you've received a scam call and "let us know about your experience".
And never, ever give personal information out to callers over the phone.