Warranty claim not handled by Audi

I bought a second Audi Q3 last year that still had about a year left on the freeway plan. After the first few months of ownership the battery began giving issues and was not charging. Took this in to Audi V&A and diagnostic tests done and battery charged over night. This now charged battery didn't last long before we had to take it back for the same procedure. So it carried on till finally a month out of Freeway Plan we took it to Audi Claremont, who advised that the battery had been defective all along and Audi V&A should have done a manual test that would have picked up the defect. R6500 later and Audi South Africa and the V&A branch have gone cold and deny that this is a warranty claim. Seriously upset that corporates treat customers like they are idiots. This is a valid claim and to hide behind all diagnostic reports etc is a poor show. Nothing wrong with vehicle, spotless and a gem, but with this poor service how can I recommend them to anybody.