Best Quick Installation in Phoenix AZ

I had these guys put 125' of curbing in my front yard while I was at work. For the most part it looked pretty good. Its not the best quality concrete mix out there but I'm thinking it will hold up. The first thing I noticed when I got home was a good sized lump right in the middle of my front yard. I contacted them and was told they charge more for any prep work and that their machine will follow the ground. I then told him that if I was contacted telling me there would be a lump in my yard I would have paid to have them take 3 minutes to level out the roughly 2-3 feet of uneven ground. They would not come back to fix it without charging me more which I understand but what I don't understand is it could have taken a 20 second phone call or text to let me know and very easily taken care of.