Looks like you could have used a new threshold. Go to the hardware store or a big box store and get a piece with rubber on the bottom, and screw it to the bottom of the door. If you have room there for a threshold with the rubber strip, that would be a better option. The first is called a door sweep, second just called an aluminum threshold.

It’s a little hard to tell but it looks like the door threshold is sitting on very uneven concrete. The correct way to do this would have been to even out the concrete, then install the door. The question is if the installation price included that step.

We can agree to disagree but I believe that starting with a flat and level surface is the best way to hang a door. Sealant is used to prevent air/moisture infiltration and fill minor imperfections. From the pic, there are gaps of a 1/4”+.

Appreciate all the comments, it was a brand new door with the door frame included. I don’t want to bring these guys back to my house. Just going to cut my losses and do the quad thing and call it a day.

I haven’t been able to find quality people to perform any repairs on my house. It’s very frustrating. 10 years of one shoddy repair after the other. I am hiring people who are well reviewed and come recommended. Such is life...

Well, you might have bought it with a door frame, but, that doorframe should have come with a threshold too. What you have is not a new threshold. Seems it is getting harder and harder to find someone to do a decent job these days. You cannot trust the reviews either. Good luck with your repair.