Poor quality goods and service

I brought guitar strings at Cash Converters, Newcastle Mall, which failed after two weeks and their response was "no guarantee on strings". Strings are new, not second hand. When I suggested turnng people away from purchasing there, the response was that I should do it if I want to and it was delivered with a tone of absolute arrogance and lack of caring that left me sick to my stomach. The lady actually smiled while she said it and there was no kindness in that smile at all.