Told customer that I’m becoming a problem when wanting to load

I went into the Rosebank The Zone store to load my mobile money account. The assistant told me with a very bad attitude that I should add more into the account because it will make banking difficult for her. So I proceeded to ask how that is my problem and she said that it’s because I’m making it her problem. I then asked her if she’s refusing to do her job and she said just for that she will not assist me and that I must go elsewhere.