Prius 2010 Radio Trouble

Hello Prius owners
I am hoping someone can help me with this. I am having a problem with the Radio in my Prius II (2010 ).
The radio was working fine, when suddenly one day it started to first produce a jarred sound and then after sometime would hang and completely die. It did this for some weeks. Now it has completely died. Completely died means that it comes on and i can change the channels but there would be no sound. also, the sound system does not work through the AUX cable when i play the songs through my phone.

i took it to the dealer and he said the radio unit will be changed. he made me sit for 2 hours and said the unit is changed. on the way back home the radio stopped working but i did not have the time to take it back. i took it again two weeks later and the dealer after making me sit for another 2 hours said that there is a rodent in my car which has destroyed some wiring because of which the sound does not work. He says that we need to call the insurance company and ask them to fund the fix. He says if we dont hurry the rodent can do more damage.

Now I dont believe a word of what he is saying.....how come the rodent just bit the wire which made the sound to stop working....everything else in the car, lights, and all other electronic is working. can someone please guide me here.