cant buy car at ridel

CANT PROGRESS IN STORY MODE ON PC!!

got to the point of starting over and buying a car at ridels

so that way you could get into the qualifier to try to get your car back 

game gives you like 38k to buy a car 

first car i purchase i get a message ""purchase failed""

2nd attempt try a car slightly cheaper then the first.. same message

3rd attempt same thing but game froze. 

so i restarted it

once it was reloaded and i went back to story mode the purchase list of cars wasnt the same

it stays in "Buy Custom" wont let me change it

so i cant progress any further in story mode 

PLEASE HELP