Bad Customer service

last week I went to buy some few clothes at Queenspark Tygervalley. I bought 3 jersey's on promotion where you buy 2 & get 1 free. the cashier advised me to open an account & she told me about the vouchers that if I buy for a certain amount i'll get a voucher. she even advised that I can return the jersey & re-purchase them on account to qualify for more voucher. the account was approved & I went to collect the card & return the stuff as per advise. at the store after they activated the card, they told me that all that information was incorrect. I left the card there & I told them to cancel the contract because it's null & void if the promise is not fulfilled. now they want me to pay R101 for the account that I will not use.