Pooling of water in shower pan

Had new shower and new pan with wall tiled in bathroom. I have a lot of water just sitting on my four curbs in shower. Also about 20 water spots in shower pan just siting there. Water is draining, but all these water spots sit on curb and in pan are not reaching drain. Installer told me that it is dreamline's fault, that their pan is lousy, and water doesn't slope all the way down to the drain. He told me he sloped the drain/pitched it, all is level. water collected in grooves in shower pan, don't know what to do. Dreamline told me the installer did not put the pan in correctly. What bothered me was that the installer shows me that all four sides of curb were level, and middle middle of shower pan was sloped since bubble was a little off center, not in middle. Installer is demanding the rest of their money from bathroom remodel. in dreamline pan, there is grooves in which water has hard time to pass through.

This is going back and forth. I don't know who to believe. Somebody is lying to me. I search dreamline shower pan issues, and not one complaint. Please let me know your observation.

Thanks,

Todd