also, when you do lay on the floor, try the "belly up" postition as it is less threatening.

Kittens that were not handled or not handled properly at a pre-weaning age can become afraid of humans. But this does not mean they cannot learn to trust. But you need to go slow and have endless amounts of patience. But it is very rewarding.

Success story #1: FERN
I do not know her exact background, but I can tell you that it toke her over 4 years to even come to sit on my lap.

Success story #2: WILLOW
He was afraid to even be picked up when I first adopted him. He hid 98 % of the time and now after 2 years he is almost as well adjusted as any other pet. (he still hides from strangers though)

Success story #3: CALVIN
Calvin came from a home and still he was not properly acclimated to people. He only knew 1 man his whoole life. He hid for weeks and would not even eat for his first 5 days here at my home. And even though I still cannot pick him up to hold him, after 1 year he LOVES and ADORES attention and petting. And he does not hide any more.

Your kitty will come around.