Very bad service

I went to istore in centurion mall because my charger was broken. It still works but its not going to work for a long while. They told me its fine they will send it in to repairs i just need the original packaging.. I took ot today and the lady who helped me between 1-2 was rude and told me no its been tampered with. I really did not pay 650 for a charger thats going to last me less than 6 months!