The Apple cash register provides an exact accounting of EVERY transaction.
Do the math.
Ask your Dad for an assist if needed.
Additionally, from your wallet card, select More (3 dots) Card Details -> Download Transaction Statement.
This downloads several months of statements itemizing every penny “in” and “out.”
If you DO find an error, contact Green Dot Bank (the issuer of AppleCash) as follows:
By calling (877) 233-8552
By mail for disputes at:
P.O. Box 9
West Chester, OH 45071
By mail for general customer service at:
P.O. Box 1070
West Chester, OH 45071