My Mitsubushi Galant was driven by a friend and the alternator belt cut and and the battery became dead and car stopped and did not start. Another battery was brought by a battery charger because it was at night and the car was driven home without diagnosis. The next day my mechanic came to work on the car but it wouldnt start. He discovered that the cut alternator belt hooked inside the engine and cut oil pump belt according to my mehcanic.  So far he has changed oil pump, fuel pump, the altnator belt, oil pump belt. Mechanic has gone to bring electrician who diagnosed and checked sensor and said I need to change the Brain box. Please who has idea what I should do? Expert opinion needed please.