what's that old saying - my Mom used it all the time. "If you want something done right, do it yourself". I don't buy kits because of all the warnings from others. One gal asked me if I would make a quilt from a kit - she would buy the kit. I said, "nope, don't work with kits" and I explained why.
I would not let this rest, that is too much money involved to just drop the matter. Definately take the kit back to the store and ask them to get the matter resolved. Good luck!