Help with toning

I use a 28 wash one , cant remember the make, yes i do use straightners whenever i wash my hair as if i dont my hair just goes frizzy

The problem with that, and using dyes and products that have silicone (which is a lot of them), the silicone melts and bonds to the outside of the hair. That means the cuticle won't lift and then the dye, once shrunk by the remover, won't leave the lair and so goes dark again. It could well be what's happened here I'm afraid.

Ok so ive done 2 strand tests , one dark purple toner mixed and the other a light shade of putple mixed , left bith on for 15 mins, the dark one was way to dark and the light one not mych different to my hair?? Shiuld i leave the light shade on for longer? Should it be applied to freshly shampooed hair that hasnt been dried??
Also why is the dye purple and not blue ?

I would try a mix that is somewhere between the two, you have to keep experimenting to get the shade and timing just right. If you leave it on for longer than 15 minutes it should last longer.