Radio Code Error
 

I took my 2011 Honda Odyssey to the dealer as the radio was not working. I noticed also that the clock resets to zero every time i start my van. The dealer tried to reset the code and they said after a few attempts and a battery disconnect the code did work and the radio started up. But after they turned the van off and restarted the engine the radio and clock reset again. It asks for the code again. The dealer is saying i need a new radio.