2002 Volkswagen Passat

My daughter just had her alternator replaced on a 2002 Volkswagen Passat. After she picked up her car from the shop the stereo is dead. No lights, nothing. Its not the security code because it doesn’t even work to input the code. She took It back to the shop they checked her fuses etc. They said it has nothing to do with them replacing the alternator and is not their problem. Which I understand to a degree, but the stereo worked just fine before the service. Am I crazy to think it might have been something they did?