Poor aftersale customer service

I bought a car two months ago at Penta Suzuki Montana & I got breakdown, took it to VW for Diagnostic. I was not worried because I bought the car with Warranty. VW found that the fault is the battery, I then tell them to contact my warranty for the claim and shockingly they warranty rejected the claim saying they don't cover for wear n tear. I then told the dealership that they need to replace that battery for me since the car was bought recently, They sent me pillar to post until I got fed up and paid that amount for battery replacement.