When Kenneth Hart learned he was on the hook for a $2,800 cellphone charge he believed was unjust, he prepared to launch a legal battle.

"I felt unfairly treated and I dug my heels in," says Hart, a psychology professor at the University of Windsor.

His provider, Telus, billed him the amount for using about half a GB of data while travelling. Hart believed the roaming charge was unwarranted because he didn't give his approval.

To help prevent "bill shock," Canada's Wireless Code mandates that cellphone providers get permission from customers before letting them rack up substantial data overage and roaming fees.

But some wireless customers still find themselves in shock when they open their bills.

"I was caught by surprise," says Hart. "I'm racking my brain as to where did the data usage come from?"

Hart brought his case to CBC News and eventually got almost the entire charge dropped.

I never said 'yes'

Hart's saga began when he received his cellphone bill in January. It included a $2,816.63 roaming charge for using .6 GB of data while in the U.S.

Hart was in New England for three days over the Christmas holidays, but says he used his data sparingly so he didn't believe he could possibly be hit with such a big fee.

Plus, Telus never asked for his consent. To protect customers from runaway charges, Canada's Wireless Code stipulates that cellular providers must cut customers off once they run up $100 in roaming fees.

Customers can only continue if they consent to paying for more, typically by responding "yes" to a text message from their provider.

Hart says he never got a text message from Telus. He did receive messages that his roaming charges were climbing. Because he hadn't approved any added fees, Hart brushed off the alerts as a scam or an error made by Telus.

"I ignored all of them and I said, 'This has got to be a mistake,'" says Hart.

When he received his big bill, Hart also thought it was a mistake, so he called Telus to sort it out.

'I am going to fight this'

According to Hart, a Telus customer service rep offered him half off his roaming charge, cutting it down to about $1,400. The university prof was still unhappy.

"I was insulted by that guy when he gave me a 50 per cent offer. I said, 'I'm not paying a penny and I'm getting legal advice and I am going to fight this.'"

Hart says the rep then revoked the offer and suddenly the discount was off the table.

Kenneth Hart says he called Telus and was unhappy when his cellphone provider offered him only a 50 per cent discount off his bill. (Kenneth Hart)

Faced once again with a $2,816.63 roaming data charge, Hart looked into hiring legal help. "I'm so angry that I'm willing to spend $1,500 and try and get it down to zero," he says.

Hart also contacted CBC News about his case. We asked Telus about the charge. More than two days later, the telecom replied, telling us that it had added a roaming package deal to Hart's account. Telus also said that the deal had been applied retroactively to Hart's bill, practically wiping out his entire roaming fee.

"When a customer has a concern, we try to work with them positively, often to get them onto a plan that better meets their needs," Telus spokeswoman Luiza Staniec wrote in an email to CBC News.

Hart confirmed that Telus did indeed cancel his big bill, a mere two hours before the telecom responded to the inquiry from CBC News.

Hart also forwarded to us a text message from Telus, informing him that he would be credited $2747.88 "as a goodwill gesture." That leaves him with just $68.75 of the original charge.

"I feel wonderful," Hart says about Telus's offer. "I'm very happy that I was my own consumer advocate and reached out to you, and that you went to bat for me," he told CBC News.

Opting out of consumer protections?

We also asked Telus why it hadn't asked Hart for his consent before letting him run up his bill.

The telecom replied that the customer had a corporate account which was set up as "notify only." That means Hart receives notifications when he incurs added charges.

But he doesn't get other consumer protections laid out in the Wireless Code: Telus neither blocks his usage when he hits $100 in roaming charges nor does it ask for his permission to continue running up the bill.

Hart gets his plan through the University of Windsor, but it's a personal plan that he pays for himself. He says he had no idea his account was "notify only" and that the roaming cap didn't apply to him. "I have no memory of that," says Hart who has has been with Telus for at least three years.

CBC News asked the Canadian Radio-television and Telecommunications Commission about the issue. The telecom regulator says that individuals can be exempt from the roaming charge cap only if they "knowingly and expressly" opt out.

On Monday, Telus sent Kenneth Hart a text message offering him a credit for almost his entire roaming charge. (Darryl Dyck/Canadian Press)

Although Hart no longer has to worry about the massive charge, he believes there may be other cellphone customers struggling with surprise bills who might learn something from his experience.

"How many people are there like me? Nobody knows," he says.

The CRTC is currently reviewing the Wireless Code, including rules around providing consent for both data overage and roaming charges.