1996 Acura RL Question: Acura Radio***Please Help

Ok, I was told by the Acura dealership that after my battery was replaced and my stereo did not work that the stereo would have to be pulled to get the serial #,So I did that but now the code seems not to work.The radio was working fine but now they are saying it may be something wrong with the radio because the code is not taking.I find this hard to believe.The car was rarely driven for the past year and now the radio just went kaput??? Does anyone relate to this or have a possible solution to this problem ?? I NOW know that whwn u replace a battery in this car it shuts the whole stereo down and I think this is pretty ridiculous!!! Can ANYONE possibly help with this?? Any suggestions would be GREAT.I can push the 1 & 6 simultaneously and it comes up with the word CODE E on the front panel and the light and security red light works!!