Zed vs Zee

"Zed!" I growled at my daughter "The letter is pronounced ZED we are not American, nor is this the 57th state of that particular country."  I was fuming. I had just read that yet another American based company had bought out yet another Australian company and was attempting to Americanize it, ZEDs and all so I was not in any mood to have my daughter and her friends singing with an American