Warranty Issues - Nissan is tedious!!!

I am so exhasted of complaining about the same Nissan due to a substandard service I keep getting! Right now I am livid! I am at Nissan Milnerton with a car under warranty and my battery is messed up. Over the last few days I called in and emailed to no response by the service personnel and I was advised that I would be called back and nothing happened. Eventyally got tired of the waiting and I drove to the dealer, and now I am being told that I have to cough up half of the fee to replace the battery???!!! I have had 3 cars so far, and never have I experienced bad warranty service like I have had in the 1 year I bought the Nissan. I cant wait to get rid of it because its costing me more to own it as much as I have all these warranties and stuff! I have had it with Nissan, Noooo Moooore!!!