Unable to stop motor through GPIO in Python

Question

I'm using an rPi to send a GPIO signal to a servo motor. When I run the program, the motor starts turning, and then continues without stopping, even if the program has terminated through the use of a loop or through Ctrl+C. I am not sure why the motor would still be getting signaled to rotate. If anyone has any ideas I would appreciate it! Code here:

import RPi.GPIO as GPIO
import time

GPIO.setmode(GPIO.BOARD)

GPIO.setup(11, GPIO.OUT)

p.GPIO.PWM(11, 50)
p.start(7.5)

try:
    while True:
        p.ChangeDutyCycle(7.5)
        time.sleep(10)

        p.ChangeDutyCycle(17.5)
        time.sleep(10)
        print "running"

except KeyboardInterrupt:
    p.stop()

    GPIO.cleanup()