Battery Warranty VW Golf 7 GTI

I had an issue where my battery was not covered under warranty. VW SA states that my original battery was not in my vehicle and they will not cover it under their warranty/maintenance plan. I have been been loyal to their brand for the past 15 years. I had to pay R4500 cash to replace my defective battery at Princess Benoni VW. I am extremely disappointed with their service. This is the last time I will be driving a VW brand. They did not even try and make an attempt to investigate the matter further.