Visa's can be processed in any country. Where a background check is required, it is done by the applicant's country, and any other countries that the applicant lived for 6+months. So in your case, just because the file was processed in Kenya, it does not mean the background check (which is not normally done for visitor's visa) was done in Kenya (unless you lived there at one point)
"I submitted an account statement of (23k to 24k cad$)": were these funds in your account for awhile (savings) or were they deposited for the purpose of visa application?
I have no relative in Canada so how do I intend to stay, like I said I'm still a student I cant possibly leave 4years out of 5year behind: Many have overstayed their visits with the same profile. Sometimes just mentioning that you are a student, or you have parents might not be enough. You need to show how these 2 are so important to you that you will have to return to them (frustrating right?). It is often more difficult for people who are single, with no children and no assets to prove ties back home.
Purpose of visit: Did you explain how/why the mentioned seminar is important to you, and how it is relevant to what you are studying? Why you need to go to Canada for the specific seminar (why not attend one in Nigeria or any other country). I've seen a lot of refusals to attend seminars on this forum, I wonder why. It can be discouraging
You can try to order your notes to know more about the refusal
all the best