Technology

I have recently purchased a secondhand vehicle that recently had the battery replaced and the radio won't work. It requires a code but I don't have the code or the radio manual that has the code in it. How do I get the code for the radio?

I purchased my first new car at 72, a 2017 Kia Cerato Sports. The sat nav was very important to me and part of the advertising was based on the sat nav. Now, the sat nav mapping is four years old and the two odometer readings on the dash disagree immensely, sometimes up to 10 km out, I emailed the dealer twice, received an auto receipt, but no contact from them. Next I phoned KIA Australia and they said it was a warranty job, but the software company who wrote the software for the sat nav is no longer. Now, I have had to obtain a Garmin sat nav and put that in the car! If the sat nav systems are in both Cerato and Rio, there must be a lot of frustrated owners. My sat nav says, "You are going too fast!” even when I am stopped at a stop sign. Just past Gympie it is 110 km/h but my sat nav says it is 50 km/h, which once was road works finished three years or more ago. I need help and advice, as I'm not getting it from KIA. Who can help?