The other day I was DTO and a customer asked for a venti water. I told him we use a one size standard cup for our water and it is 20 oz (maybe this is not universal but we have done it since I've worked there). He asked if I was sure about that since he has ordered a venti water before from us. I said I was sure. I inform customers of this all the time and the usual response is "oh ok! That's fine then." Or maybe they'll ask for two of them. But he was pissed and asked to talk to the manager and what my name was. My manager was busy and I didn't want to bother her over free water so I said I would just give him the venti. It was annoying and he continued to be rude at the window too just kind of extra the whole time. He asked for a side of almondmilk and a receipt and kept saying my name mockingly and rolled up his window. Anyway, I have a feeling I will have to deal with him again or even worse someone else will. I wish I had handled it better so as not to be dreading potentially having the same issue with the same nasty customer again. I have no idea why he was so mad about free water but then I saw him dump his double espresso into the venti cup which was funny because he actually wanted a tall iced americano in a venti cup and that would have been easy enough to order with no issues. I'm just wondering how more experienced partners deal with customers like this? Usually things go pretty smoothly and customers seem to like me and vice versa. So I'm not sure what triggered this.