Ignorance and attitude

First I would to understand, who is a customer between me and a sales lady. I took my time yesterday after work and I went to Markham at Calton centre to pay my account, first the que was very long and when I finally get to the point of sale, the lady by the name of Puleng asked me why am I not greeting with an attitude, I told her im not there to greet but to pay my account. She gave me that attitude look, then I told her I want to pay R1000, the kept quet and just push the speed point for me to insert my card myself, well I did that and she processed it, after that while I was walking out I noticed that shes luaghing, then I wondered what she was laughing at, then I decided to check my receipts only to find out that she processed R100 I then asked for the store manager who was not so helpful, I asked them who's supposed to be double charged.I want action to be taken on this, I really can't tolerate ignorance. I need a constructive feedback as soon as possible, My details are as follows, Mr Paul Makhanya Contacts numbers : ********** 898