Replacement car battery collapsed before expiry

In December 2013, I bought a Dixon car battery for my motor vehicle from GWK Co-Op Mechanical Dept in Prieska, and I was told that the battery is sold to me with a 1(one) year guarantee. After a period of barely 8 months, the battery collapsed. I took it back to GWK Prieska, it was tested, found that the battery must be replaced, and I was given a new Dixon battery, free of charge. However, the date of purchase of the first battery was scratched onto the new one, but my complaint fell on deaf ears. Now, after 9 months of usage of this replacement battery, this battery also collapsed. When I took the replacement battery back to GWK to be tested, it was found that the battery must be replaced. But, I was told that the guarantee was only applicable to the first battery, so they refused to supply me with a new battery, free of charge. To my opinion, this is unfair, because every battery on their shelves, should go with a one year guarantee. This means now that I have to purchase a new battery all over again. It is no fault of mine that they keep this bad products on their shelves. Please help me with this.<br> Thank you.