Aggressive staff

I was at the EVETECH shop today to purchase a new PC advertised on their website. I spoke to Francois Bothma. He told me it will take them 3 days to assemble the PC from the components I asked for. I told him that I need the PC today still and I'm willing to assemble it myself. He then told me that the PC will cost R1000 more (PC was advertised for R18000) if I want the components. I asked him if I could talk to a manager to negotiate this price difference as I am willing to spend more on the components but I am not willing to pay a R1000 penalty to get the PC the same day. The next moment he points at another customer in store and tells me that this man is willing to pay and they have customers paying R1000K for PC's and none of them complained like I do. At this point he also states that he is the store manager. I asked to speak to the owner as I did not appreciate his insult. He then told me that I must leave or he will remove me from the store himself!!! I told him that I was not being aggressive at all and that he is overreacting. I could see his immediate realisation and he just sat down and ignored me. As I left the store he gives me a sarcastic \have a nice day"."""