Help!! Reverse gear at Carisma.. can no longer be switched…

Hello, I’m back.. once I talked to you about our new Lancer.. to my satisfaction.. Now we have another problem.. the old car – Carisma, which now drives the daughter.. does not, if you want to take the reverse gear… at the beginning.. have you tried a few times and it went.. now does not want any more.. ( An expert said, new gears should go… and says of price between 500-600€ can that be true??? Is the car still to be saved? the daughter is in the move..and so something..does all plans go through each other (Can you help me??? Give advice ? why.. doesn’t the gang go anymore? what can it be?? Helpeeee :..(((((((((