Okay you really need to
READ the Rejection reasons carefully :
"Given your academic performance,your language ability in specific bands and proposed course of study."
1. Given your academic performance : Whether your University looks at you meeting a certain percentage of marks in math etc the Visa officer is basically going to see it as "
Computer Science". Some may have the patience and understanding to realize that math counts but another would look at it as a whole and be like Science - Poor, Math - Just above Average and English - Lacking skills -
REJECT. I'm not trying to demotivate you but this is the hard truth. No one is going to god father you.
2.
Your language ability : Please do retake the IELTS and give your very best. Do not go with the impression that you need to score the "BARE MINIMUM". Go with a clear mind, its really not that tough. Try and score a good 7 - 8 band. you will feel confident too about it.
3.
Proposed Course of Study : This again is in Co relation to Point 1. You will have to write a genuine yet convincing SOP where you state the absolute truth as to why you do you want to take this course up and also justify your grades. Do not belittle yourself but be humble. Try and show that you are willing to give your best with this opportunity to pave way for a brighter future and change your academic performance. Also that you wish to take back to your home country what you will learn in this great Canadian University.
Do not change your University just because of this rejection, never compromise on your education just because you want to get into the country. The visa officer will immediately doubt your
credibility because it will reflect that you were accepted yet you changed your University and reapplied.
I do not understand, you said you are two years late? But you have graduated this year!
P.S : You have to revise your SOP and include all three points of the Rejection Mail,
Best of luck !!
Feel free to clarify any doubts.