Not sure if my idea is good...

If you want the manager and sales person be punished, but do not want too much trouble, you can write to their CEO/President directly. (Will this work?)

You probably can sue them on small claim court.

You probably want to take some photos of their shelf to show that they are still selling the products; with other date telling evidence in the same picture. (You probably need to be careful doing this. For example, pretending making cell phone calls and shotting photos.)

I am really not sure my ideas are good or will work. Listen to others.