I doubt a "recalculation" or "based on what I have observed at home" is going to go anywhere, though you can try.
We had to spend the $$ to privately test our youngest daughter when they declined to put her in the gifted program in 1st grade. The same daughter who is now in 8th grade and in DYS, SET, captained the school math team, MVP at Academic Games Nationals, outscored the average district student by 425 on the SAT, etc.
Sometimes they just get it wrong. Private testing or waiting out the re-test period are the likely options.
