Just take the car to either a Peugeot specialist OR an In Car Entertainment specialist - the former may be familiar with the issue I am sure the latter would be - an aftermarket replacement may be the way forward though the value of the car and the cost of a replacement may bring difficult choices. I doubt an aftermarket jobby will retain the availability of the steering wheel mounted controls ( presuming they are there already ) - also an aftermarket replacement may not have all the bells and whistles - eg satnav or reversing camera - there are ways around that though but again at cost