The legal aid clinic Juripop sent Uber a formal notice demanding that it reimburse clients in Montreal who paid "deceptive, abusive and disproportionate" fees on New Year's Eve.

If Uber doesn't comply by Feb. 28 Juripop lawyer Marc-Antoine Cloutier said he will pursue a class-action suit against the car-hailing service.

The non-profit clinic is representing Catherine Papillon, who claims she was charged $82.20 on Jan. 1 for a ride that would normally cost about $10 with a regular taxi. Another 20 customers have also contacted Juripop for support, it said.

Papillon and Cloutier are asking Uber to refund all customers the difference between the fare charged during the New Year's "price surge" and the regular price.

Catherine Papillon said it was her first time using Uber and didn't understand its dynamic pricing on peak periods. (Radio-Canada)

On busy nights, Uber raises its prices to encourage more of its drivers to get out and meet the higher demand. On social media, users said the price surge on New Year's Eve was as high as nine times the normal price.

According to Juripop, Uber "clearly profited unfairly from its dominant position in relation to users who have accepted the terms of the contract, which is a clear violation of its duty to be loyal to them."

"A party that adheres to a contract cannot consent to an unfair clause, regardless of whether it has, or should have knowledge of it," Juripop said in the notice, basing its argument on the Quebec Civil Code and the Consumer Protection Act.

Uber will not comply

A spokesman said that users are clearly advised of price increases and must consent to them on the mobile app. Users are also given the choice to be alerted if prices go down.

"Uber was a reliable option to take people home safely on New Year's Eve," said Jean-Christophe de le Rue. "This would not have been possible without the dynamic pricing."

He added that tens of thousands of Montrelaers used Uber to get home on Jan. 1 and that the average price increase was 2.2 times the normal fare.