Extremely rude employee

Absolutely disgusting service received by the African women working behind the counter at the post office today in the morning glen shopping centre. My box could not open due to it being rusted and I just asked for assistance in knowing if she could tell me if I had any packages there. She was first on a personal call on her cellphone and then when I told her the situation she refused to help me and said I cannot use a post box that does belong to me. It is my grandfathers post box and I am entitled to use it. She had a disgusting attitude and then proceeded to scream at me. She would not give me her name and I am appalled that you can hire someone so rude and *********** of speaking to customers with some respect.