Ignition lock cylinder repair fail?

I have a 2003 Dodge Neon. The ignition lock cylinder needed to be replaced. I bought an ignition lock cylinder that goes with my car. Of course I have the so called smart key, therefore I will have to rekey/recode the new lock cylinder with the tumblers that came with it. I carefully took out the tumblers from the old cylinder and put them down in the specific order that I took them out. I then put the new tumblers that came with the new cylinder into the new cylinder in the same order that the old tumblers in the old cylinder were placed. I had to do this because I guess I have that smart key and had to try to rekey/recode the cylinder so that it would work with my old key as the new key wasnt a smart key. Anyway, I put the new cylinder in and now its locked in place. I cant take it apart like I did before. I just decided to put the old tumblers back into the old cylinder and use that until I can figure something out. Well, now my old cylinder wont even unlock. Now Im screwed and cant use my damn car. Why would the cylinder just lock up like this? Is there a chance that I coded the cylinder incorrectly? But even if I did, shouldnt it still be able to come apart easily like before so I can try recoding it again? Also, can I get some estimates on how much either a dealer or repair shop will charge for a new ignition lock cylinder plus a new smart key which I now also need? Or is there a chance that they would be able to take apart the cylinder that I bought and work with that?