I lost all my cop exept for one.

i was playing as cop and i had just completed the 8th assignment and watching the movie VRT called in and skipped it. i entered the car menu and the only car i had was the Mercedes-Benz C63. Then i drived out in that car and completed assignment 9 and watched the movie go rouge and skipped it. i entered the car menu and then the only car i had was the racer ferrari enzo ( i was playing as cop). 

so i would like to get all my cars back.