Call your boyfriend and see if he still has the box for the dye. There should be some sort of info number that you can call on it. If he doesn't have it any longer, go to a store and copy the number off of a new box. Then call them and tell them your problem. They will probably be able to assist you.
If somehow there is no number, then I guess I'd just cut my nails as short as possible. And wear nail polish until the dye wore off. Shouldn't take that long for the dye to wear off or for the nails to grow out enough so that you can trim off the black part.
If none of those sounds good, then the last thing I might try is a haircolor remover, which they might sell at the same store that sells the dye. Or something from the laundry aisle called Color Remover, though I've never heard of anyone using that on nails.
Go to a sewing or notions supply store and buy a package of Rit Undye. It is made to take the dye out of cloth or off ob
Take drastic action, chop them off with an axe.LOL
if it has come off your hands but is still just on your nails...cover it up with nail polish. or see a manicurist. they might have ideas.
Patience, patience. These things take time.
tsp, pick it off........or an overly enthusiastic boyfriend