Missing barrel nut - Aero Precision AR15 Enhanced M-LOK Handguard/ Barrel Nut Not Included

Why is a handguard even sold without a barrel nut? I thought when I placed the order that I specifically requested the hand guard with a barrel nut. Somehow in the process of waiting 2+ months for the order to be filled, I ended up with a handguard with no barrel nut. Moving on, I figured I could go buy a barrel nut and move forward. No such luck, everyone is out of stock. Except Optics Planet who happens to have them in stock for $40+ shipping, and taxes..... so, now I'm stuck in a spot that I cannot finish building the rifle, unless I pay $60+ to Optics Planet to get the required barrel nut. Typically, Optics Planet is pretty good to deal with on most everything that I order, but occasionally I have an order that just goes to badly. Apparently I was due to have a bad experience this time around. So a word of caution to make sure of what you are ordering.