Charger not working

In 2014 December I bought a charger at an istore in menlyn only to find out later that the charger is not Apple certified and the charger no longer works with my phone and today I went to the store to report my malfunctioning charger and they say they cannot help me as I'm not loaded unto their system with any history of purchase. Then I told them it means the lady(who happens to be the one helping me now) did not load me because that was actually my first purchase at the store so now I have wasted R270 for something that only worked for a month and the customer service at the store is super poor and the staff's attitude is also in my view bad as I am also a paying customer.