The mother of a student from Woodbridge, Ont., says she is upset after her daughter and four friends were charged $446 for an Uber ride without being warned about the company’s “surge pricing” system.

“I was upset about it,” said Nancy Giatti, who had to pay the fare. “It’s not right.”

Giatti said her daughter and four friends left a nightclub in downtown Toronto on Friday, Oct. 30.

The students opted to get back home to Woodbridge using Uber to save money on a cab ride that would normally cost about $120.

Uber is usually less expensive than traditional taxis, but the ride-sharing service’s rates are based on demand.

“When demand for rides outstrips the supply of cars, surge pricing kicks in, increasing the price,” Uber Canada spokesperson Susie Heath told CTV News.

At regular prices, the cost of going from Woodbridge to downtown Toronto using Uber is between $45 and $60 one way. But when the students used the service at 2:30 a.m. on a Friday night, surge pricing meant that rates were five times higher than normal.

Uber said the students should have known about the increased rates, based on the way the app is designed.

“Riders are always required to provide consent to the higher price in the app before they are connected to a ride,” Heath said.

But Giatti said surge pricing wasn’t explained to the students. Otherwise, they never would have agreed to the increased rates.

“They asked the driver just to make sure that it wasn’t going to be an outrageous amount of money and the Uber driver told them not to worry about. It wasn’t going to be much more than $96, so they agreed to the ride,” Giatti said.

For full-time students with part-time jobs, the cost of the ride was more than they could afford.

“They were hurt,” Giatti said. “They felt ripped off.”

Uber connects app users with people who have signed up to be drivers using their own vehicles. UberX, Uber Canada's most-popular service, has been operating in Toronto for a year.

When Giatti complained to the company, she was given a 25-per-cent refund. But she said she has advised her daughter to stop using the service and to go back to taking regular taxis instead.

“I don’t think that it’s fair that people have to pay that type of money to get home,” Giatti said, “especially when they’re being responsible and not drinking and driving.

With a report from CTV Toronto’s Pat Foran