Netflix question !!!!!!!!!!!!!!!?

2 months ago i put the my netflix info on my friends ipod 4g. he paid me 5 bucks that month and said he was gunna pay that everymonth. So every time he clicks the netflix app he automatically signs in with my account. Hes not gunna take him self off my netflix and he doesnt let anyone see his phone niether. I tried disabling the device but he can still watch it. So that didnt work. How can i freeze the netflix account on the iphone. sign him out. is there a way? changing the password is going to help either