Horrible service

Last year in March Williams Hunt bought a battery on my behalf at Battery Centre in Port Elizabeth and I was told the battery has a 2 year warranty and today they are playing hide and seek because they don't want to renew the battery. They asked Opel to take the battery to them and they charged the battery and the battery is doing the same thing and they are still requesting Opel to take the battery to them, for what exactly? Why is it difficult to replace the battery? Must the battery be taken to them every time it doesn't charge. If there was a zero star I would rate them zero.