I work for a company and have a delivery route (rental of uniforms ,the customers takes the same delivery every week as does all my other accounts)and my employer has put my full name on the invoice without my consent(my customers have seen me week in week out for 5 plus years)I have told them I don't want my last name for all to see can I make them stop this practise?

No, you can't.

Your employer is entitled to use your name to identify you to its customers.

How would you have them do it?