Inside a combination lock are tumblers which should be lined up after you dial up the numbers. What sometimes happens is the lock may tilt slightly on the mounts if someone twistes hard on the open latch. The answer sometimes is dialing it off 1/2 number. Had a quebec manufactured safe do that. Screws that were to small for the holes in the lock. put a mark with tape on each side of the dot and dial up your numbers.

Sure blame the poor kid.
Think about it, what good would a safe be if by pressing a few keys the combination was changed?
As with any combination safe you need to clear the combination by turning one, two or three times in the opposite direction before entering the combination.

Now say your sorry to your kid.