C++ Switch-Case statement problem?

Not a c++ programmer but you are not igning AnnualMiles a value of R S G at any stage so it will not trigger any of the case statements (you seem to be igning R the value AnnualMiles<30000; not AnnualMiles any value other than original input). you need another variable and ign values of R,S,G to it and use that value in the switch statement