You can see on the left side of the picture there is an evenly spaced indention in the material. So it is possible that something is happening while it's rolled up. I'd still say they likely didn't store it properly. Possibly even wrapped the banner around the stand itself.
Briteline has it's good materials and bad. It's pretty ignorant to say everything BL is bad. Personally, I prefer their roll-up to other brands. Their 3203x installs better than ij35c, not failing to mention the awful smell of the ij series. The window perf outlasted and was removed easier than some 3m perf that was installed next to each other at the same time. I keep asking them to create something to replace ij40 so I can stop buying that too.