Sorry for the confusion. So here is the story..
Well, I actually paid online keeping in view the paper application for TRVs.
Then decided to apply online which will not accept the earlier receipt and only directs me to pay online (again) and does not have provision for the receipt I already paid (as it was valid for Paper apps), so I had to for the online application again and ask for refund of the previous ones.
I sent a mail to HPM.PROD@cic.gc.ca but they never replied or send any acknowledgement of the mail.