Need Correction Please. Unit 6. Department Store.

Hi teachers,

Could you correct this paragraph please?

This is a department store. It opened at nine o’clock and closed at five thirty. It is six o’clock now. The department store closed half an hour ago, so all the shoppers have already left the store. They left it half an hour ago. The sales people have counted their money, have given it to the sales managers, and have gone home. The last one left fifteen minutes ago. That was at five forty-five.

In the text we have, 'The sales people'. Is there a singular form to name just one person? Is it salesman?

Thanks in advance