You cannot void or return incorrect paid ins or paid outs. The only way to reverse an incorrect paid in/out transaction is by performing an opposite transaction (paid in to correct a paid out, or paid out to correct a paid in) for the same amount, which will re-balance your day end totals and cash amounts.
Example: If you meant to do a $50 paid out, but accidentally entered it as $500, you can do a $450 paid in which will balance the incorrect amount and leave you with only the intended $50 paid out. The incorrect transactions will still show in your day end records, but the amounts will balance correctly, the same as if you had never made the original mistake.