Smart Start Inc. Screwed up my car because of negligence Irving, Texas

SmartStart installed a breathalyzer on my car on two separate occasions. The first time they installed the unit on my car it was brand-new in only had 1600 miles on it. When installing the wiring on the car they cut the wire harness going from the cabin of the car to the engine compartment. In doing so it set off a bunch of false codes causing me to have to put my car in the shop when it was only three months old. After a lot of work the dealership was finally able to show them where they screwed up my car. The second time the unit was installed on my car the technician who install it was careless upon installation. Along with pulling wiring harnesses loose he also pulled the drain tube loose underneath the dash that connects to the firewall from the sunroof off its outlet. The next time it rained all the water from outside drained into the fuse box underneath the steering column because he didn't reattach the drain tube. I have documentation from four different mechanics including the dealership placing them at fault. The technician who installed the unit also admitted fault. All the water has caused my car to be out of commission on and off for five months. I have had to miss work and borrow cars from people along with countless amounts of gas because of this issue. I never once asked for reimbursement for lost wages or gas money because of this but only wanted my car fixed to the condition it was prior to their screwup. Because of the water damage caused by their negligence the car needs a new wire harness that SmartStart refuses to pay for. Not only did the manager refused to pay for it but he told me to take my business elsewhere and he would see me in court.