Assurion's insurance plans are typically purchased at the time you purchase the phone. Since Public Mobile only offers the actual cell phone service and not devices, it wouldn't make sense for them to insure products they don't sell.
I was with Virgin before moving to PM. I had a decent promo plan, which was $45/month and hand unltd Canada-wide calling, texting, and 1 gig. I barely call out of my province, but could use more data, so I switched to PM and have province-wide callin...