compared with you, i think i am too lucky. we have 8 CS staffs totally. in my eyes, they are all very responsible, and show their professional side on work.
sometimes i also think IF i had a tought staff, what could i do? I am a nice person, have very mild temper, don't know how to shout at people to show my toughness. people always say DON'T BE TOO NICE TO YOUR STAFF, OTHERWISE YOU WOULD FEEL DIFFICULT TO HANDLE. i just 50% agree, i still believe we need to show differnt attitude to different people but always with respect.
for your two difficult staff, i agree with the three steps, verbal, written warning and then onto termination.
looking forward to hearing from you soon! :-)