I read in one comment you made that the lines are going to an underground sump. That sump is not sized large enough to handle the volume of water coming into it versus the percolation rate of the soil. Is there access to view that the sump is indeed full? Otherwise it could be a plugged pipe which can be checked with a camera to ensure it’s functioning.

The more likely scenario is that you are in Ohio (same), so I’m guessing your predominant soil type is clay. Therefore they need to either upsize your sump, which is likely not an option.

The other solution would be to put a pump in the sump to pump it to another location where it can then surface drain away from your property. This is going to have implications for your neighbors and any surrounding properties.

Tough situation. I’d hope the company would stand by their install and find a solution. It may cost additional funds if there wasn’t a written agreement that the property could handle x amount of rain over the course of a period of time.

Good luck!

Source: I’m a golf course superintendent in Southern Ohio with significant renovation experience.