Had my heater serviced—$150+ a part o/l was $9.95, was charged $

Lower - Had my heater serviced—$150+ a part o/l was $9.95, was charged $30 for the part. $180 total & he wouldn’t take anything but cash for payment! Hmmmm, wonder why. Can’t help but wonder how much seniors, especially, are taken advantage of!!! Sad-sad-sad!!