After watching the fireworks competition from downtown Ottawa last Wednesday, a group of friends went to eat tartare and have a glass of wine.

It was just after midnight when Crystal Grierson and her friend hopped in an Uber to begin the 20-minute drive home.

In the morning, Grierson woke up to an email from the rideshare service saying she'd urinated in the back of the car.

"I emailed them right away wondering what was going on," she said. "Nothing irregular or unusual happened."

According to her driver, that wasn't the case.

Crystal Grierson said she feels 'completely wronged' by the rideshare company and plans to take legal action, if necessary. (Crystal Grierson/Facebook)

Uber told Grierson that she had vomited in the back seat of the car, then corrected the claim, saying it actually was urine.

They had charged her $170 for a trip that cost $20.

"I was completely shocked, I wasn't expecting that at all. I didn't even know Uber could charge you without investigating anything," she said.

Cleaning inconveniences drivers, Uber says

She asked the company to review the accusation, as both she and her friend could confirm that neither of them made a mess in the car.

Uber responded with photos of a wet seat the driver had sent them.

"Cleaning fees are assessed and charged according to the extent of damage. When this happens, drivers are unable to accept trips and must spend time cleaning up messes or having them cleaned instead of picking up riders," Uber said in an email.

"These fees are based on nationwide industry averages for professional cleaning and drivers receive the full cleaning fee that you are charged."

Two similar incidents have happened in Toronto this year. In both cases, riders were charged $150 extra to cover the costs of cleaning up a mess they didn't make. Uber refunded one of the patrons for those charges.

"I was in a car, nothing happened and now I'm being charged for urinating, of all things," Grierson lamented.

Uber said it refunded Grierson the full amount after CBC News contacted them, but she said she's yet to receive it and her request for additional information about the incident has so far been denied.

A spokesperson for the company said it was "continuing to look further into this situation."

Reimbursed for something she 'never did'

Grierson has taken to social media and intends to make formal complaints with various levels of government.

Many people who commented on her Facebook post said they will start boycotting Uber alongside her.

"When the driver is able to make money off of innocent passengers, it's just not right. There's no way to regulate it, there's no way to escalate it," she said.

"[It's] sad that it has to come this far before they will consider reimbursing you for something you never did."