07 ZO6 transmission
 

My 07 ZO6 transmission shift fine going from 1 thru 6th gear,but when I put in reverse it backs up fine but want come out of reverse even when put in neutral. Have any one had this problem before on their and could you help me please. I have the car at the dealership and they said I need a new transmission @ $4500. It only has 56K miles on the car