Childcare Centre - Fetching Child From Preschool

Just want to rant Whenever we fetch our children from their preschool, we will need to press on the door bell and somebody inside the school could see us through the glass door and some may recognise us while some may not and they will approach us at the main door to ask who we are fetching. Recently, I have encountered an experience which I felt it’s kinda rude at the same time looking like an idiot in front of other parents. I’ve reached the school, pressed on the door bell, and there was someone standing in front of the reception counter. She didn’t look at me from the inside of when the door bell was pressed, ( the door bell could be heard from the receptionist counter) after a few minutes of waiting for her eye contact, she told me she had called for my children and I told her that, oh, I didn’t know you already saw me and she replied she saw us when we were walking towards the school. In my mind I was pissed and feel like an idiot for blocking in front of the main door just to wait to tell her I’m here for my children and was thinking the least she could do was to just give me an acknowledgement when i pressed the door bell instead of me standing in front of the main door waiting for her to look at me. I don’t have any special power to know that she had already saw me. I’m wondering if I’m overreacting? Do you all think that this is a rude behaviour? How would you deal with this situation from happening again? Thanks for reading.