Missing phone

I upgraded my phone & plan online June 18, my email confirmation said it was shipped June 20 via Canada Post with the tracking number. I've been monitoring Canada Post website and the expected delivery date was June 21. It never arrived so I waited a few more days and still nothing arrived. Canada Post website said item delayed but nothing has been updated in the system since June 21. I contacted Canada Post agents and submitted a ticket which would update once my package was scanned. The agent yesterday said there was an influx of packages and lack of staff which is why my item is so delayed but we're going on 2 weeks now. Canada Post emailed me this morning that the next step is to have the sender - Koodo initiate the next steps which is submit a claim. Has anyone had experience with this? What do I do? How do I contact someone to help we with this?