The reason you did not get results was you were already using a black rinse in your hair.

If you've already used ANY artificial pigments on your hair, you WILL HAVE TO BLEACH IT OUT.

The hair stylist colouring your hair should know this!!! Did she not even ask you if you had coloured your hair before?

A good colorist will decolorize your hair with a bleaching shampoo concocted with shampoo and bleach. By applying while your head is in the sink, she can watch as the colour lightens to the level you need to go to for your desired result. THEN she can tone your hair to the right shade.

I would be concerned about doing this at home after you've already treated your hair twice with permanent colour which is already damaging enough.