I saw a similar product years ago and though it sounded too Murphoid for my tastes. Given the cited weight and size wasn't too much below what a good ultra-light sleeping bag is it seemed technologically redundant and unlikely to degrade with wear gracefully. That it is One-use-only tends to cement in my mind that it isn't very durable to begin with.

Interestingly I saw reviews of a similar product and they didn't have the sort of problems you have with it falling apart when opened. I suspect that the bag you got was old and the plastic in the laminate has degraded over time. I would package it up and send it back with a demand for a refund. It is unacceptable as shipped.

Thankfully you were made aware of its shortcomings before it was needed to fill a critical need. Shades of "Catch-22" where the first-aid kits and parachutes had been replaced with IOUs.