THANK YOU CARD? YES !!! PURCHASE ON ACC? NO !!!!

I hate the fact that each time you purchase something at any edgars store, they ask if you have a thank you card and they automatically assume that you want to purchase using your account card. As such the incident i experienced on the 21/03/2015. I bought gifts which i wanted to purchase using my bank card but the lady already charged the amount to my edgars account and then made me pay the amount due of R560.00. I asked the lady how is that possible as i received my statement for March 2015, saying that my instalment due is R580.00.Bearing in mind that i did not have much credit available, i did not want this charged to my account! as i am trying to pay it off. However i would like to know how is it so difficult for your staff to have the courtesy to ask before processing something and to follow instructions. I am wondering if i were to believe the lady as she said i do not have to pay any amount further this month, would i then go into arrears at the fault of some *********** person !!! I demand that constructive feedback is given to me regarding my account and what is expected of me , if this lady has put my account in exceeding credit available , i want this to be sorted out.