Customer service care

I’m still in shock after what the store manager in Sandton was shouting at me for his mistake , what I believe could have been Easley fixed . Instead of saying I made a mistake I under quoted you will it be possible for you to pay the difference; ended up him shouting at me while I was trying not to be provoked by his behavior the entire time ,It was like I’m dealing with a child in his terrible two’s only it was an adult. I’m still trying to figure out what happened why was behaving in that manner! I never thought questioning someone about what I interpreted what was said in the email could result in him saying what he did.