HELP! Need opinions from colorist!

  Hi everyone I am new!  I need advice from professional colorist?

I am 44 years old and I have been using the same colorist for 2 years now and she has always done a fabulous job.  I have naturally dark blonde hair and have been coloring with two different colors for a long time, a highlight and a lowlight, to create a sun-kissed blonde color similar to Renae Zewelger when she is blonde.  In early December of this year I had my hair colored and it was perfect as always.  But then my colorist moved to a new salon, and in late January, she claims she used the same product, Redken, and the same colors, but it came out very different, the low-lights were and light brownish, with a little red in it????  When I called to tell her something was not the same, she was very upset and offended and said she didn't know what I was talking about?  She first said that it was probably my hormonal changes or because I was in the Sun in St. John in December.  But I have had my hair highlighted for a long time and have been in the Sun many times and my hormones and medication- prempro- I have been on for over a year with the same dose???  Nothing even remotely similar happened. 

Then I went in to get a clarifier and more lowlights over the dark done by her after she was so insulted, because she kept saying that it's just a little darker then your used too, it's not like it turned green or something!  Anyway everyone noticed my color was different so I know it wasn't me.  The few hightlights worked a little in the front and on top, but the back remained dark and when it started to grow out it was darker then ever before.

Now I decided to stick with her and work it out, so I went in yesterday and not only did the same thing happen, but also it looked like I still had roots all over, just not as grown out, when I mentioned that to her she said my natural hair has turned darker and that is what I am seeing???  But I was seeing grey, I know I am probably getting greyer, but darker????  And the dark that was left over from the last time should of been corrected.  When I told her I was not happy and it still is not coming out like it has always looked in the past?  She freaked and said that I am insulting her intelligence, she has been doing hair for nine years, and it is my natural color that I'm am seeing.  I said I don't buy it, and I don't know what to do.  She if I don't want to see any natural color I would have to bon or bone it?????  When I asked her what that will do, she said she could not explain it because I wouldn't understand, but thats what I would have to do from now on because my hair is darker???? So she put I think bleach in all the root for 5-10 min. and then washed it out.  At that point, I said everything thing is fine, because she said she talked to her manager and if I'm not happy I need to go elsewhere were her words.  I was not crying or yelling or even visible upset, I just felt I needed to be honest, how else do I get back to the result.  She also said everyone there says I'm BEING DIFFICULT I didn't want to be difficult, just was not happy with the result.

Now I have a light bleached blonde look all over, it is not bad, but still not what I am use to.  HOW CAN MY HAIR GO DARKER AT 44, AND IN ONE MONTH????  I AM GETTING MORE GREY, BUT DARKER, AND SHE ALSO SAID MY BACK OF THE HEAD HAIR IS DARKER THAN THE FRONT??  BUT IT WAS DARKER FROM THE BEGINNING, BECAUSE OF THE LAST COLOR, AND THEN SHE PUT A FEW MORE HIGHLIGHTS IN MOSTLY IN THE FRONT AND ON TOP?????

I WOULD OF WORKED WITH HER, BECAUSE I LIKED HER AND REFERED A LOT OF CLIENTS TO HER OVER THE LAST COUPLE OF YEARS.  BUT SHE HAS TREATED ME LIKE I AM CRAZY, SO FOR THAT, AND HER INSECURE EGO, SHE KEPT SAYING YOUR ACTING LIKE I DID SOMETHING WRONG, I WILL NOT GO BACK TO HER, BUT I'M TRYING TO FIGURE OUT THE WHOLE PROBLEM?????????? PLEASE HELP!!!!!!