Brake Light On problems of the 2016 Chevrolet Traverse

We bought a used vehicle from acadiana Mazda, lafayette la. About a week from having it the emergency brake light comes on. We bring it in, they say they can't find anything wrong so we take it back. The next week, the salesman gives us a call and says that they need to replace the windshield, after asking for a sales ticket for several days, they give us a sales ticket from the week before that says that they think the vehicle has a water leak. (service ticket is enclosed) I come home that night before bringing it in and I find rust dripping from the emergency brake, standing water under my flooring, rust / corrosion all over the bottom parts of the car. What is suspected by the car dealership is that the windshield wasn't sealed right and when it would rain it would come in from the windshield and drip down through the emergency brake. We figured there were 37 days of rain since they had it and all of that rain was going into the vehicle. I was not informed of this prior to buying the car. I tried to return it but they refused and wanted to fix it. That was just sealing the windshield, the brake sensor and replacing the flooring. I did not feel that was good enough. To avoid a legal battle and concerned for my family's safety, I traded it in. I believe there may be some electrical issues, and other concerns with the car that they will not fix so I am reporting this for someone else's safety. It may also have been flooded but that wasn't disclosed when the first owner traded it in but that is just speculation. Please investigate.