I am having the exact same problem, its been going on for months. When I turn off the hot water tap the water still flows out.
I had someone come to look and they said because of the type of tap (ceramaic) I would be just as well to fit a whole new sink and taps (which is fine with me coz I was planning to do that anyway). He said it would be v. expensive to fix.
Heres a helpful piece of advice....
What I fathomed out was if I turned on the leaky hot water tap on full, the went to another hot water tap in the house (i.e in the bathroom), turned that on full, then went back to the kitchen tap and tried turning that off it stops running.
Hope that helps!