If you can't get your Dad to see reason, you might be better off thinking about moving this snake on to a new home where it can settle.
What is going on now is a form of animal cruelty and for the sake of your snakes health, a new home could be the nicest thing you could do for it.
Maybe look at getting a calmer snake instead if your Dad can't see this. Good on you for recognising there is a problem here.
