Canada Post Lost Iphone 16

I purchased the iphone 16 in September and it shows it was out for shipping with Canada Post September 26th, in my City. To date, I have not yet received my phone, I paid nearly $1500 up front and am being billed $20.00 a month for easy financing on a portion of it. I have called numerous times and initiated an investigation. Every 5-7 days they tell me they need more time and I'll get an update in 5-7 days. At this point I just want to cancel my order and be done with this, but I'm told I can't until they finish their investigation. How is this my problem? I am out a mortgage payout essentially and have no phone still. It's been a month since this process started. I am beyond frustrated. I should be given my phone while you are investigating. Not have to wait months for answers.