MONTREAL -- As of Monday, Quebecers 80 and over who got a first dose of the Pfizer vaccine can book a second shot sooner than originally planned.

At least, that’s what’s supposed to happen.

Instead, on the first day of rescheduling, several people say they haven’t been able to get through the online booking process and are facing long wait times to book over the phone.

Several residents have expressed frustration on social media towards a booking process apparently rife with kinks and error messages.

Laval resident Rosalind Warhaft says that after about two dozen attempts leading to error messages and "please refresh" prompts, she’s still without a new date for her shot.

"I am so frustrated," she said. "I've been trying and trying and trying and it wasn't working."

"I said, 'maybe it's my computer,' I had another friend try to book it for me, and they couldn't."

Many have expressed concern around technical issues with online booking, which can be especially frustrating for seniors who might be less comfortable using computers.

Warhaft said she’s actually very good with a computer and has booked several appointments for her less tech-savvy friends.

"I'm teaching an iPad course at the senior centre so it's not that I don't know what I'm doing," she said.

ONLY CHANGES TO PFIZER DOSES ALLOWED FOR NOW

Quebec's ministry of health said in a statement to CTV News Monday evening that it is aware of the "technical challenges" on Clic Santé website and the phone lines and that a fix is on the way.

"Many thousands of people who wished to do so were able to move up their appointment today," the statement read. 

The ministry also said that advancing the date of the second doses is, for now, only available to people who received the Pfizer shot as their first dose.

Changing the date of the second appointment is not mandatory since the original date of people's second dose will still be honoured. Health officials also recommend people do not switch the type of vaccine for their second dose. 

As for changing the date of Moderna doses, people will have to be more patient. The ministry said additional doses of the Moderna vaccine are expected "shortly" and people will be able to change their second dose appointments once more supply is available.

People who received an AstraZeneca vaccine at least eight weeks ago are eligible to get their second doses at various walk-in clinics, which are still offering the vaccine. If people who received a first dose of AstraZeneca want to change the type of vaccine for their second dose they will have to wait until their initial appointment to change it. 

For those 80 and over trying to take advantage of being at the front of the line, time is running out.

Each day this week, the minimum age requirement to reschedule a second dose gets lower.

"Oh my God, I started last night," said Monteregie resident Brenda Lee, who spent hours trying to book an appointment for her father-in-law.

Like Warhaft, Lee said she received several error messages on Clic Santé, making it impossible to confirm her appointment.

"It would say ‘error message, reload page and try again,'" she said, adding that she spent four hours over two days trying to book.

"It was very frustrating because I could see the appointments online going one after another," she said. "And I'm going 'great. By time I get someone to make the appointment for me, the appointments will already be all gone.'"

With files from CTV Montreal's Joe Lofaro