C :: How To Get Upper Case And Lower Case Equal

I just dont know how to get my upper case and lower case equal...heres the program: Write a program to calculate utility cost for ACME UTILITY COMPANY. The company has 3 types of customers (R) residential, (C) Commercial and (G) government. Customers are billed based on the number of kilowatts used and they type of customer they are (R,C,or G).

Residential cusstomers are charged 0.25 cents per kilowatt hour for the first 500kw used, and 0.35 cent per kwh for all kw used over 500.Commercial customers are charged 0.22 cents per kilowatt hour for the first 999kw used, 0.29 cents per kwh for all kw used over 999 kw up to 1999 and 0.45 cents per kwh for all kilowatts used greater than 1999. Commercial customers that use over 2000 kw are charged a special surcharge of 100.0 in addition to the regular charges.

Government customers are charged 0.34 cents for the first 1500 kwh used(<=1500). 0.30 cent for the next 1000 kwh(1501-2500) and 0.25 cents for all kwh used over (>=2501)

in addition residential customer are charged .5% tax on the cost utilities while Commercial customers are 5% tax on the cost of utilities not including the special surcharge Government customers are not charged a tax

Code:

#include <stdio.h>
#include <math.h>
int main(void)
{
int R;
int ct;
int kwh;
int taxes;
int surcharge;
int charge
}

[code].....

the program should quit with Q and calculate the amount owed, utility charge, and surcharge