How can I get my hair to stay red?

I recently just got auburnish red hlowlights on top of my blonde hair. It literally lasted a week before it faded. I'm not sure what I am doing wrong, I don't wash my hair every day and I don't spend long hours in the sun. I know red will fade especially on top of blond hair, but jeez, a week!? I spent money to have something disappear! I'm not sure if it's just my hair or the dye that they use because I have never liked the way my hair turned out when I went there, I work in a place with a salon so I get a discount which is why I went there in the first place. However, ever since I have gone I have never liked the way the color made my hair look, it was dull and the blond never looked vibrant like it used to.

I just found out yesterday that a girl in my class is a cosmetologist in my area and she told me that they use Matrix color. She told me that since my hair already had a red base that the red color would most likely adhere better and last longer.

So my questions:
1). Is what she said true, will the color adhere better and last longer?
2). Has anyone ever used Matrix color before? She told me it was anti-fade, so can anyone attest to this?
3). How can I find ways to make the red hair color last longer? She told me I would need to use a heat protectant serum because I straighten my hair everyday.

I don't like spending money on something that isn't going to last and will end up being a waste, but I really like red in my hair, it looks so cute!

Thanks for any replies.