RC Landscaping

I hired LeBlanc Construction, my neighbor, to level two areas and put in a retaining wall in my back yard a 80'x54' space to be completed over a Thursday/Friday. The retaining wall was quoted at $600 for Allan Block, $200 for the skid steer, and 8 hours at $25 an hour for a bid price of $1000 (An amazing deal, and thus with 5 other much higher bids I took their offer believing it was a good deal). Ruven (RC Landscaping) showed up Thursday morning at 8:20 slightly late. We discussed the project and Ruven said whatever I had agreed to with John was good and that is what he was here to do. He began working, I left and came home at noon and he had already left, however he had Paverstone beside the scratch line (an inferior Home Depot product that costs a fraction of Allan Block price). I immediately contacted John and said I was not happy. To my dismay he replied that Ruven said he had talked to me and I had said go with a cheaper product. Ruven did not show or call on Friday and instead contacted me on Saturday. He then showed up Sunday morning close to 9am and we discussed the blatant mistake, instead of having him take the product back and get the correct product knowing they were going to absorb the cost I felt bad and gave them the option of adding another layer of paverstone to the top of the retaining wall. I also informed Ruven that I had ordered sod from Craven Landscaping and the Concourse at 10 cents a square foot but would need the yard completed that day. Ruven worked til 11am and was gone by noon. Ruven showed up again Monday morning finished the project by 1:30pm and left. I work in the south bay area and had informed him I would be back Thursday to pay him. On Wednesday he called me in the middle of my shift and demanded that I pay him $1800. Ruven cost me a quality product (Allan Block) and I missed my opportunity for sod at an unbeatable price. I would recommend to not higher this company or Le Blanc Construction.