You can add exceptions to the Do Not Disturb Mode, so that only selected numbers or contacts are allowed to go trough.

Put it in quiet, vibration-less, mode. That's technically not DND and alarms still work ;)

in addition to what SirChris already mentioned, iPhones will have a setting to allow repeated calls to go through do not disturb, so it might be worth checking if your phone also allows for that?

Maybe your battery can just 'go flat' when you go to bed.

Let me guess - The reason Dad made that rule is that he expects to wake you via phone and do not disturb prevents that… Guess what, your phone has alarms - Use that to wake you at the appropriate time. That will ultimately take care of what Dad was trying to do… And every time you get a scam call block the number on your phone. Then you won’t get a call from that number again. Also scammers don’t usually leave a message so if you get a phone call from an unknown number and they didn’t leave a message it’s just about guaranteed to be a scammer so those get blocked too. You can’t completely eliminate scammers calling but you can eventually get them under control if you do this.

check your dnd settings you can allow certain people thru like ur favorites or if someone calls twice in a row