large navigator; audio part defective

Hello I own a CV year 01.05. In the car is a large nav with touchscreen screen installed. For about 6 weeks I no longer have a radio reception and was therefore already with my dealer. All antenna plugs were checked and you finally came to the conclusion that the audio part should be exchanged. cost between 650,- – 800,- Euro. Unfortunately it is no longer possible on guarantee because the car has just exceeded the 3 years. Also my client’s request was rejected. The advertising slogan would have to be called Toyota – nothing is possible anymore! Now to my question, does anyone know who else changes such an audio part? Or does someone else know another solution, because everything else works CD/CD changer/Navi except TMC reception front rear camera. Or can someone recommend me another DVDRadio that I might be able to install. Thank you Frank