Help, my cat won't eat Meow Mix!

She much prefers 9 Lives, and gobbles it up whenever she can get it. But I want to give her Meow Mix, and she always turns her nose up at it. I feed her Meow Mix on Monday, and she won't eat it. I feed her Meow Mix on Tuesday, she won't eat it. Repeat Wednesday through Sunday with the same results. I just don't know what to do. Please help.

-Tom P., Washington, DC