Unfair costumer service and rude manager

I pawn my generator for R2000 at Brits cash crusaders last month July, I lost my contract page that they gave me, I went to them on the 11th August to check the expiry date in order to extend the days, but one of the guy who help me said it is still well covered then I said I'll come weekend witch it is today 15th August, only to find my generator on sale. When I ask, they told me that is been on sale for three days now, then I ask them to speak to the manager because the guy who helped me confirmed that he checked the expiry date for me but he made a mistake of not printing a copy for me. but I was surprised that the manager told them that he can't speak to me after they made me to wait for him 45min,when he comes back from where he was, he went straight inside the shop and again after few minutes they told me that he's eating and he can't talk, all that I should do is to buy it from them and when I ask them how, they ask double amount to R 6999.95 and told me that the date expired on Wednesday so is not their problem. When I ask for the manager, the manager never come to speak to me, so that I can explain to him that the guy who attended me in the shop on Tuesday didn't have a problem when I said I'm coming weekend to extend the days because it is still valid.