Suggestion: Feed live. If it refuses rats, try a mouse. If it refuses a mouse, try an asf.
I appreciate your honesty. These animals are not for everyone.
If your son really loves ball pythons, is it possible to trade it for a more strong feeder? I know that the more picky eaters aren't the best pets for first time owners. I understand your frustration. But either way, please do not starve this animal willingly or experimentally. As an owner, you've taken the responsibility to care for this animal to the best of your ability. Keep offering food or rehome it if you cannot continue to care for it.