Size 21 for ruger ec9s - Bianchi 100 Professional Holster

Bought the Bianchi 100 holster for my Ruger ec9s. Size chart told me size 21. When I received it the trigger guard was not covered. Questioned the gun shop owner who checked with salesman. Was told size 21 was correct and even though the guard was not fully covered it was safe because the trigger was covered. This did not match their pictures showing a completely covered trigger guard. I do not like to carry in this holster with one in the chamber.