Mr. Singh
Dont try anymore for a longer duration... These all refusals are just the evidence for Visa Officers that anyhow you want to Enter into Canada.. & with too many refusals you never get visa approved... on very 1st stage they will considered the last decision of your previous visa application..
I can only suggest you to hold for a time being & mean while make your documents stronger to show them your financial status.. CIC only want how strong your finance is to travel Canada...
Consider this and my advise do not try anymore..
Rgds
SETH