display more true if statements in the same textbox ( Windows Forms app) c#

Question

I'm trying to make a change calculator in windows forms app where i need to show in what bills the customer will get money back. My problem is that the textboxt only will show one value from my if statements.

e.g

if the customer needs 644 back it only says 1 500 kr. where it was supposed to show like: 1 500 bill 1 100 bill 2 20 coin 2 2 coin. Hope you can help :)

public void cashCalculator() {

        fiveHundreds = exchange / 500;
        remainder = exchange % 500;

        twoHundreds = remainder / 200;
        remainder = remainder % 200;

        hundreds = remainder / 100;
        remainder = remainder % 100;

        fiftys = remainder / 50;
        remainder = remainder % 50;

        twenties = remainder / 20;
        remainder = remainder % 20;

        tens = remainder / 10;
        remainder = remainder % 10;

        fives = remainder / 5;
        remainder = remainder % 5;

        twos = remainder / 2;
        remainder = remainder % 2;

        ones = remainder;

        // if statements to sort out what cashtype that will be shown in lblCashType:

        

        if (ones >0)
        {
            tbxCashType.Text = ones + " Enkronor";   
            
            
        }
        
      if (twos > 0)
        {
            
            tbxCashType.Text = twos + " Tvåkronor";
            
        }

      if (fives > 0)
        {
            tbxCashType.Text = fives + " Femkronor";
            
        }

      if (tens > 0)
        {
            tbxCashType.Text = tens + " Tikronor";
            
        }


      if (twenties > 0)
        {
            tbxCashType.Text = twenties + " Tjugolapp";
            
        }

      if (fiftys > 0)
        {
            tbxCashType.Text = fiftys + " Femtiolapp";
            
        }

      if (hundreds > 0)
        {
            tbxCashType.Text = hundreds + " Hundralapp";
            
        }

     if (twoHundreds > 0)
        {
            tbxCashType.Text = twoHundreds + " Tvåhundralapp";
            
        }


        if (fiveHundreds > 0)
        {
            tbxCashType.Text = fiveHundreds + " Femhundralapp";
            
        }