Manager very rude to customer

I wanted to book in my Samsung S3 in because it didn'twant to charge. The manager of Samsung store in Mall of the North in Polokwane told me that there is nothing wrong with my phone and that it is charging on his charger. I tried to explain to him that if i use my chargers that i bought with the phone it doesn't want to charge. he was so rude and asked me where i bought my phone i told him that is a MTN contract phone he told me that if you buy from the service providers you never know what you buy. so i asked him are you saying that they are selling pirot phones he said yes it could be. I was shocked and went to MTN and asked them if they are selling pirot phones and they were also furious because he blames them of selling pirot phones. The manager didn't want to give me his name he said i can just complaint and say it is the manager for Samsung store in Mall of the North Polokwane. I don't think this brand need someone like this it is just damaging their name