Help with my hair,was medium brown but now rusy ginger, given the wrong advice has left me ginger?

my natural colour is medium brown, but i want to try being blond for a couple of months or longer ? i have been using a blond coulor three times over thelast too months and its just a rusty ginger , help how do i get the blond coulor i want , genuine answers only please, the advice i was given hasent worked ? thanks PAULA T