My 3 1/2 year old little girl is in the same spot. If I continually ask if she has to go, and physically put her on the toilet, she will tinkle in the toilet... but if time goes by and I forget to ask, she will go in her pull up. And only twice in about a year has she gone #2 in the toilet. I'm at a loss as much as you are. But I think, I hope, it's getting better. She seems to ask to go potty herself when we're out... at Church, in a restaurant, or at someone elses house...
I'm also trying very hard to get her to wear regular underpants... and let her see what it feels like to be really wet or dirty... But, it's winter time... and most activities are indoors... and we have white carpeting in many parts of the hosue... so I'm not thrilled with the idea of the accidents...
Persevere, is what everyone tells me... My mom says, by the time they're 18 years old, they can all go to the bathroom by themselves!!
Good luck!