Finally on 28th January I got a call from them saying they are not able to locate my package. I gave them proof of delivery which showed it was signed by S Schuiteboer. I learned that that's a mail receiving and sorting company that works for IRCC.
Today is 30th January and they are still searching for the package. I hope they find it today, because for me countdown has begun.
I have no clue why they aren't able to find the package. Looks like my application is running through all sorts of issues. Luck is really against us.