It depends on what you want to make with it and how you are going to quilt it. I find 80/20 easier to FMQ with. Polyester if it's low loft, will be fine to hand quilt with and even good for FMQ projects. It really is a personal preference with batting.I would contact the company and tell them of the mix up. If they will allow you to keep the poly and send you the ones you really wanted with no extra charge, then I'd be happy. If they want you to send it back, make sure they will pay for shipping it back because it wasn't your fault.