Freezer not staying frozen?

I have put ice cream in the freezer frozen, then go back and get it out the next day, and it will be real soft. The first time I just wrote this off as a fluke, but then, I just bought a new ice cream, and dipped into it last nite, and it was hard as a rock, but dipped into it tonight, and it was mush. Also the turbo cool lights is staying on all the time.