Soak immediately in cold water with a bit of washing up liquid. Leave for a while, then scour with wire wool. I've burnt loads of pans in my time, but rarely had to throw any away
Initially, cleaning a burnt pan is a pink job. But when there is little in the way of results, ("I just can't get this pan clean!"), it becomes a blue job. ("Here, let me do it, dear.) That's invariably what happens in my house!