That True , but the funny part they didn't refuse me on that groundYou have a Bachelor's degree and are applying for a diploma program which is a lower level of study. Your plan of study does not make logical sense and can be interpreted as a reason for refusal.
they refused me for
• I am not satisfied that you will leave Canada at the end of your stay, as stipulated in subsection 216(1) of the IRPR, based on your family ties in Canada and in your country of residence.
• I am not satisfied that you will leave Canada at the end of your stay, as stipulated in subsection 216(1) of the IRPR, based on the limited employment prospects in your country of residence.