Quality, but.... - Reptilia Saddle 1301 Mount For Mps & Acro

I recently purchased this saddle to go on a 20ga Beretta A300 Ultima. It does not fit the receiver. The mounting holes line up, but does not hug the receiver like it would a larger 12ga. I called Reptilia and they were friendly but said it fit both that the receivers were same size. That just isn't correct. BEWARE...This mount is for 12ga only.