Toyota not willing to replace my battery that is only 18 Months old

I bought a Toyota Hilux 2.8GD S brand new in October 2017 . The car is only about 18 Months old and the battery has died already. They have quoted me about R1 300 because it is out of one year warranty. This is really bad service, I have driven many cars before, some of them for more than 4 years and I have never had to change a battery.