Yeah, this is where some pre-bent kits differ from others. Crab, COR and Protofab preassemble the cage in a jig. I know crab marks and numbers every tube as I have heard this reported several times.
I am guessing that none of your tubes were notched to get you started.... It sounds like your shop left some length on each tube for you to fit...problem is thats the most difficult and time consuming part of building a cage---FITTING. Assembling a properly fit cage should be a simple process. Without having a tubing notcher, a drill press, etc. fitting can be very tough. If you are adventurous, take a look in the tech section at Pirate4X4.com, there is a great tube tech article there and see if you can use some of those techniques to get it fitted. IF you havent started assembling yet--no wleding or cutting has been done-- I would send the cage back...there are great cages that are easier to assemble for only slightly more $. Good luck. Post some pics, if you can; maybe some fo the folks on here can help get you on track. Could be educational...of course at your expense. Again, good luck!