I want my refund

I purchased 4 T-shirts at cotton kids on the 21st December . I returned 2 as my son did not like them . I requested the lady at the till to refund me . She took my card and did the refund. I left the store. Returned a few hours later as the money was still not in my account. I asked the sales reps why the money is still not in my account and she then told me it will take 7 working days for the money to b in my account which I find totally unacceptable as I was not advised of the T & C' s wen being refunded. All those ladies could say is it's our policy. I now sit with this issue unable to buy my son the T shirts he wants because of their incompetence. All they could say is they forgot to tell me I won't get my money immediately and that they do not do cash refunds. I WANT MY MONEY