faulty goods

this a complaint i would like to log regarding a bad attitude & lack of emphathy from a so called manager called Joseph Tsoai.i went with my brother who is the account holder for the goods he purchased on credit(sound system brand LG)the amplifier was faulty he was replaced with anothe new sound system on the 09/05/15 ,then again on the 17/05/15 the amp gave problems,so we went there to get clarity as can they not replace it with another brand or something else,he said to my face i'm not going to talk to you i'll just talk to the accoung holder,when i asked for his name he point me to the wall where there was a certificate that had his name & surname,he did not show an managerial skills at all,was not willing to assist or give assurance to his client..amazing enough when my brother was put on temporary lay off at work they were willing to talk to me when we made arrangements for time being he was unable to pay his instalments..the \so called manager"was so rude in a manner that he was even wearing dark sunglasses inside the shop swinging his chair while we were talking to him..to add on everything their collectors are so rude that they don't greet"