app\models\Client::updateBalances PHP Method

    public function updateBalances($balanceAdjustment, $paidToDateAdjustment)
    {
        if ($balanceAdjustment === 0 && $paidToDateAdjustment === 0) {
            return;
        }
        $this->balance = $this->balance + $balanceAdjustment;
        $this->paid_to_date = $this->paid_to_date + $paidToDateAdjustment;
        $this->save();
    }