Battery Dead problems of the 2015 Kia Motor Optima Hybrid

On December 5, 2018 my car suddenly stalled while driving in an intersection. I immediately tried to restart it but was unsuccessful I had battery power, all of the GA restart it but was unsuccessful I had battery power, all of the gauges would a cycle back-and-forth whenever pushing the start button,however it was just like the gas motor would not fire. It is still under warranty, so I had it towed to a dealership. The next morning I was called and told that it showed a lot of codes, and they would need some time to decipher them and would notify me with results later. After about five hours I was called back and told her that the battery on the car was dead and it would not take a charge. Play then informed me that the battery on the car was the only thing not under warranty and the new replacement was $400. Unable to pay that much for a 12 v battery I tried unsuccessfully for a week to argue the fact that the battery was not dead when it went out and getting nowhere I finally bought a $200 battery, and installed it myself. I am mediately tried to start the car. . . . It did the same thing it did after it died a week prior. I am form them after giving them the key to the car back and I need new battery and it still would not start. A nother week went by and finally I was told that they was taking the battery I purchased out to put a kia battery in the car to see if it will start (which they said that allowed the car to start). Then stated to me that after it started they were able to pull codes on it and it had a bed safety fuse. I was five minutes from the dealership whenever I was notified of this so I'll stop by nearly as I hung up the phone. When I walked in I walked straight to the car which was in the garage and look at my battery that I purchased was still in the car, had not been removed and I started the car. Successfully. I was still told couldn't take car.