That's pretty wild! I'm glad they hooked you up quickly!
Ive been bit by similar problems before when buying hardware at a local hardware store....... so now when I buy bolts with nuts to match them, I thread every nut on to every bolt / screw before I buy them. Several times I got home only to get half way through the project and then find a nut or bolt with boogered up threads. @&*^*&^!