Upvote:4
Two things:
1) Visa refusal letters in Canada do not tell the whole story of why your visa was refused. You need to request your actual case notes. (See here or Google "CAIPS request"). There are some complications with requesting these notes outside Canada, but there are companies that help arrange the process for you for a small fee. Unfortunately the process takes a long time (about a month as far as I know).
2) Before re-applying, talk to a Canadian immigration lawyer. The lawyer will probably want to examine your previous application, maybe decide to wait for the notes (#1 above), and maybe even decide to appeal the existing application instead of submitting a new one. It is expensive, but if you reapply yourself you risk a 2nd rejection and this seriously hurts your chances of getting into Canada.