I had an angry customer on the phone today, I didn't handle it very well and it has caused a major surge of self-doubt. I think the things I said probably only made him even more angry. He was sent on to me by someone from another department who gave me too brief of an overview of the situation but I was also only half listening and then suddenly I had this angry customer on the line and I could hardly follow what he was saying. The system didn't have very clear notes about the situation either which I feel like I shouldn't have revealed to him but I had no idea what to say. I vaguely remember the colleague mentioned what I should've tried to make clear to him but I was completely overwhelmed. I said all the wrong things.

Yes I'm new and still learning and yes it's a difficult situation for anyone but I feel so ashamed over how badly I handled it and like a complete failure.