Too keen with my credit card..

Had a small accident in December. My car is going to the panelbeaters tomorrow-2Feb 2016.<br> My insurance gives me a hire car which I arranged to collect yesterday from Avis at OR Tambo.<br> I was asked to pay a R1200 refundable security deposit. I gave the assistant my credit card. He put the card in the machine, pressed all the buttons, gave the machine to me for my pin. I checked that the amount was R1200.<br> All in order, I punched in my pin. I get a message on my phone from the bank confirming the R1200 transaction, and then....another message from the bank for a transaction from Avis for an additional R3000-00 odd. Something funny going on. Luckily I check my phone for these messages, or I would have been none the wiser. <br> Asked for a refund. Apparently a refund can't be done on the weekend. They can draw money from my account on a weekend, EVEN MONEY I HAVEN'T AUTHORIZED, but they can't return it to me. this was all blamed on a mistake by the counter assistant George. Smells very fishy to me....Avis that money had better make its way back to my credit card today or this is going to get a whole hell of a lot worse very quickly!!!