Weak mount broke - Truglo Tru Point Green Laser/Light Combo

I installed this on my rifle's Picatinny rail on a Sunday and bore sighted the laser.
The following Saturday I prepared to go to the range and the light fell off when I removed the rifle from the safe.
The screw that holds the light to the rail was broken in two. The screw is very thin and appears to have separated upon installation. I contacted Truglo and they accused me of over tightening the mount. They agreed to replace the entire unit and told me to ship it back. They wanted me to pay the return shipping!
I did not over tighten and I don't believe I should pay return shipping on a warranty repair. I also suggested to Truglo that they could send me the screw and I would replace it myself. They refused.
I contacted Optics Planet and they graciously sent me a shipping label so that I could return the item for credit. I will buy a different brand of laser / light combo for my rifle.
I will continue to do business with Optics Planet.