Hello, this is actually your mistake. Such mistakes can be costly. The main visa section has released your passport, that's why they can't give you any proper information.
However, did the embassy inform you which courier/mailing service provider they used? Or they have standard agreement with some courier company? If you're sure about the mailing service provider they used, just go to their office in your city and they will help you track the document and return it back to you. The document has your full name, so it won't be a problem. Otherwise it might be wrongly delivered and discarded or if not received by anyone, it will be sent back to the embassy. This process can be longer and when it gets to the embassy, it will also take longer for the embassy's clerks to contact you.
My advice is if you can't verify from the embassy about the mailing service provider and you didn't include prepaid envelope, then verify from other applicants you might know who already received their approved permits through mailing or contact the Canadian Visa Application Center. The embassy might have some particular mailing service provider. They just don't post using any mailing provider. Good luck!
. I phoned and e-mailed them, and all I received is just some useless information. It had been 1 month passed since I got the e-mail, could anyone give me some suggestions on that, thanks.