Placed an order and 2wks later no stock

In the beginning of Oct I placed an order with HomeChoice for a towel set buy 1get1 free that I saw in their booklet, and agreed for the cash payment to be debited from my acc on the 25th of October. Two weeks later I get notified that unfortunately they don't have stock after I received the confirmation sms's etc, so the way I see it is that just because I did not pay the cash immediately my order was diregarded and given to someone else who paid then and there which is totally unacceptable. Now they they still have the audacity to phn me and ask me if I don't want something else and that is not a solution to my dissapointing experience with Homechoice.