Rented equipment return issues

I sent the package enclosing the rented equipment for the internet contract that has ended earlier this month. But it has not been delivered since it the tracking showed up “out for delivery” on Jan 21 on Canada Post tracking system. I want to get a confirmation that my return will be processed properly.

Also, I forgot to put the paper with the account information written. Can you trace back our account information only with the shipping label and the equipment(router) identifier?