Well, you've got a lot going on here.
I assume you arrived at the airport and were sent into secondary screening where they checked through your phone.
If they said that you did not declare a US visa rejection on your visa application, I imagine the visa was likely cancelled. Normally they would stamp on the visa that it is cancelled, but you can also find out by logging into GCKey and seeing if your document is still valid.
Finding text messages about a work permit is also not a good thing, when you're arriving as a visitor. You can assume that you are flagged in Canada's immigration system now and will have a hard time getting into the country or ever getting any kind of temporary visa or permit to visit Canada.
If you did commit misrepresentation, you may have also been banned from applying to return to Canada.
What paperwork did the CBSA officers give you? What does it say on it?