Generally, 1 year programs don't count but there are exceptions and so the details matter. And, it is also possible that they made a mistake. You have not provided enough details for anyone here to help you specifically determine if your rejection was correct or incorrect so review the following and then get back to us (or a consultant/lawyer) with your details.
1) From IRCC's website regarding TR to PR Pathway eligibility criteria:
Graduation requirements
To be eligible
- you must have graduated on or after January 1, 2017, from an eligible program at a designated learning institution (DLI)
- you must have been authorized to study for the duration of your studies
- your school must
- be a DLI. Check the DLI list to make sure your school is on it.
- offer post-graduation work permits (PWGPs). You do not need to have a PGWP in order to apply.
Eligible programs
To apply through this stream, you must have graduated with
one of the following:
- a degree (Associate, Bachelor’s, Master’s or Doctorate) with a program length of at least 8 months
- a degree, diploma, certificate or attestation leading to a job from the list of eligible trade occupations
- a diploma, certificate or attestation for a program that was at least 2 years (16 months) in length
- two or more diplomas, certificates or attestations where each program was at least 8 months in length
- a diploma of vocational studies (DVS) or an attestation of vocational specialization (AVS) where each program was at least 1,800 hours in length
- two or more DVS or AVS where each program was at least 900 hours in length
- When combining 1 AVS with 1 DVS, the length of the AVS program may be less than 900 hours if the combined length is at least 1,800 hours.
2) You have the right to Procedural Fairness: https://www.canada.ca/en/immigration-refugees-citizenship/corporate/publications-manuals/operational-bulletins-manuals/service-delivery/procedural-fairness.html
IRCC's rejection letter should provide you with details on why you were rejected. After doing your homework above about the details of your Study/Graduation, if you still think an error has been made, you should let them know based on their own criteria (point by point) that you believe you are eligible and provide whatever additional proof you think is required to correct the matter. Unless you are very good at letter writing and proving your points, I suggest you may want find a consultant/lawyer to assist you in this.
3) It's not over until it's over! My personal experience with IRCC making an error was not on TR to PR but on a Study permit extension in July 2021. The agent believed that I was not in a qualifying full-time program because they misunderstood the meaning of a heading on my transcripts. I politely but clearly pointed out their error and also had the Associate Dean of my program write a supporting letter explaining that the heading used on the transcript column did not reflect the program of study and that the Program information was on a different line. It took some patience and back & forthing, but the situation was corrected.
Best wishes!