Mercedes Forum - Mercedes Benz Enthusiast Forums - Key stopped working after changing the fob.

So I bought a new fob shell because my old one is damaged and was covering the buttons with tape. So ordered a new shell, drove to my moms where I had it delivered and picked it up, drove back to my house and got it into the new shell no problem. All the buttons were working including the trunk release which was a blocked off button on my original shell but when I went to start my car it wouldn't turn. Ok cool, I'll put the board back in the old shell and see if it works. Old key shell now no longer starts my car either. Changed the batteries, then the lights stopped blinking and now no longer unlock my doors. Anyone know what I can do other than go to the dealership and get them to order me a new key. Panic button still works but no other buttons. The IR still flashes when buttons are pressed and holding the lock and unlock button will cause the red light on the fob to blink.

Its a 2002 C230k