A B.C. mother says a Greyhound bus driver forced her two young daughters off an Alberta-bound bus in the middle of the night last weekend, abandoning the girls at a remote truck stop not far from the Highway of Tears.

The sisters, aged 12 and 16, waited alone for almost five hours while a family friend drove through the night to rescue them.

Greyhound has launched an investigation, but a spokesman said it appears the girls' tickets had expired.

"I never, ever want any parent to have to go through this. I don't want any child to have to feel how my children felt," their mother, Vanessa Aubichon, told CBC News as she wept. "I'm furious. I'm sad. I'm upset."

Aubichon's daughters, Chelsie Kazakoff, 12, and Jessie Kazakoff, 16, live with their father in Alberta, but were visiting their mother in Prince George, B.C., over spring break.

Aubichon bought them round-trip Greyhound bus tickets at the Prince George depot. She said she asked the clerk to set the return date for Sunday, so the girls would be back at their father's house in Sylvan Lake, Alta., the night before school started.

Girls left on overnight Greyhound

While Aubichon was at work, family friend Brent Valkowsky saw the girls off at the Greyhound bus station in downtown Prince George. He watched as the driver took their tickets and the girls boarded the overnight bus, which left Prince George at 12:05 a.m. on April 3.

Several hours later, the girls were scheduled to change buses in the dark at a Greyhound stop at a remote gas station and fast food outlet in Valemount, B.C., at 3:35 a.m.

Aubichon said the girls boarded the second bus for the next leg of the trip to Red Deer via Edmonton.

But she says the driver told her daughters their tickets had expired and his bus was fully booked, so they'd have to get off.

Aubichon says the Greyhound driver told the girls that if they waited in Valemount through the night, they might be put on a morning bus that would get them back home to Alberta in 23 hours.

You don't just leave two girls behind. Who does that? - mother Vanessa Aubichon

That's when she fielded a frantic phone call from daughter Jessie.

"She's like, 'Mom, Mom, the bus driver left us!' You could hear it in her voice. She was absolutely scared.

"The fact they could leave them like that, with nowhere to go, knowing they have no one.

"You don't just leave two girls behind. Who does that? Who does that?"

'I don't have a clue where they are'

Aubichon said she was in a panic.

"I burst into tears. I was in hysterics, hyperventilating. I don't have a clue where they are. I don't know what to do because I don't drive."

Aubichon managed to reach Valkowsky, who owns a truck, and a second friend who agreed to drive, and sent them off to Valemount, a three-hour drive, in the middle of the night. The town is about 20 kilometres south of Highway 16, known as the Highway of Tears due to the number of unsolved murders and disappearances of women along the route.

"I just panicked. I cried. I was in hysterics, " said the girls' mother, Vanessa Aubichon, above. (Betsy Trumpener/CBC News )

Aubichon said she spent the next few hours calling her daughters and weeping.

"I cried myself right out. I paced my floor the whole time, back and forth, back and forth."

Her friends arrived in Valemount to rescue the girls just after daylight.

"I could see they were scared," said Valkowsky. "As soon as I got there, they just hugged me and wouldn't let go."

Valkowsky and the friend then drove the girls to their father's house in Alberta.

Meanwhile, Aubichon tried to reach Greyhound. She was told by a customer service representative that Greyhound would consider giving her a refund if she filed a formal letter of complaint.

"I don't even care about the money," said Aubichon. "Do you understand what you just did to two little girls?"

CBC News contacted Greyhound at its corporate office in Dallas, Texas.

Greyhound 'taking this matter very seriously'

"We are taking this matter very seriously and are currently conducting an investigation to find out exactly what happened," Greyhound spokeswoman Lanesha Gipson said in an email.

Gipson said an initial investigation shows the girls' tickets expired two days before they travelled. "With the second bus at capacity, we had no empty seats for the customers to travel."

She said the driver "still wanted to be helpful and called the driver of the next scheduled bus, who agreed to transport them."

"Because our tickets are date and time specific, we encourage customers whose travel plans have changed to have their tickets reissued for another date," said Gipson.

But Aubichon said Greyhound staff should not have let her daughters board the bus in Prince George and travel the first leg of their journey if the tickets had indeed expired.

"The lady who sold the bus tickets, the driver who took the bus tickets, nobody paid any attention," she said.

Aubichon said she wants to ensure no other young passengers ever go through what her daughters endured, and no parent suffer what she did.

"Absolutely, I had my fears about putting them on Greyhound," she said. "But it was my cheapest way of getting them here."

"I urged them to take the bus because I wanted to see my daughters so badly. And this is what happens."