I checked with VFS as well and they asked me to drop an email to Canadian embassy about cancelling the Visa, I had done the same but didn't got any response yet. Further, I checked with my bank stating that my visa expires on 31st Mar'21 and till that time if I am not able to get the visa cancelled letter, what needs to be done. The bank said that in such a case, I can upload the expired visa copy after expiry date along with a letter directing that I will not travel to Canada.
Therefore, waiting to get a response from embassy or visa to get expired.