The ignition key turn all the way back, stuck?

I have a 2004 Cadillac CTS that wont go into gear. I tried to start it and it wouldnt start, so I looked under the hood and noticed it was a bad connection to the battery. So I wiggled the cables and it powered back up. But then it locked my doors with my keys in it. I was able to get a hanger through there and unlocked it and started it and tried to put it into gear, and it wont go, and my keys wont come out of the ignition and the dash has a lock light on it, and it says the security system needs service. What do I do? Any suggestions?

I have the same problem with my caddy did you get yours fixed? I am at wits end with this problem.

I'm a shop owner that has the same problem with an 03 model we've tried different keys and doesn't work I found that sometimes the ECM goes out is that true?