Jigga, I understand your frustration. Unfortunately, you've gotta take a step back and figure out what you want to do now. It sounds like you've got a TurboXS downpipe, no TurboXS midpipe, and a 5Zigen cat-back. Did you buy directly from TurboXS? If so, I would've thought they would've sold it as a package. If not, then whoever you bought the downpipe from might have screwed you over for not telling you it wouldn't mate up to your cat-back. With that said, I think you've got a few options:
1. Sell your cat-back, and buy the rest of the TurboXS exhaust
2. Sell your cat-back, buy the TurboXS midpipe, and buy an axle-back of your choice
3. Sell your TurboXS downpipe and buy a different downpipe, such as an HKS, Godspeed, Perrin, Stromung, PDE, etc
I hope you get it all figured out, and I really hope someone didn't screw you over when you bought the downpipe from them without the midpipe.