My company does not pay my sales commissions until the customer pays them. My argument is that I do not control/participate in collection, and they should pay my commission when I make the sale, not when they collect. Are there any laws that support me on this? I'm employed in MO with a MO company. Thanks!

Nope.

It is common for commissions to be based upon receipts.

Now if the laws stipulated that you got paid based upon closing sales and that the receipts of the revenue did not matter, I, as an employer, would cut your commission rate to compensate for the revenue I will never collect on the sales you closed.

Bottom line -- sell to folks that will pay.