Advanced optics rd3-020 - ADE Advanced Optics RD3-020 Raptor Red Dot Sight

I used this sight only once, when i intiall mounted it and was in the process of zeroing it in. The red dot functioned well for several magazines through a Glock 17 however, The dot began moving upward in the dispalay window eventually settling all the way at the top. This was after approximately 30 rounds fired. I attempted to adjust the sight but the adjustment screw failed to move the dot before it eventually hit it's adjustment limit.
I was not previously familiar with the ADE brand and bought this item based primarily on price. I will not replace this item with another ADE optic.