Bad Service

My name is Tebogo Ravele I bought school uniform for my son in Ackermans Westgate yesterday to my surprise the items where bigger sizes. I came to Ackermans Lakeside to do exchange only found out that there are no sizes at all then I asked for a refund as I could not find the sizes, I spoke to a cashier she referred me to a Store Manager she told me that I need to bring the card that I purchased with as the debit card is not in my possession and I need the cash cause I got the sizes in another store. So I don't have the debit card they can't help me the manager told me that there is many ***** happening at the moment so they can't assist me she wont even authorise that, my concern is that every customer buying in Ackermans can create ***** if they using debit card according to the manager I have a proof of purchase items are still in the original packaging. Now at the back of the slip it does not states that I need to bring my bank card. The slip states "We will gladly refund or exchange any item in a saleable condition within 30 days, provided you have the original till slip" problem is that now I have to buy the uniform for my son hence I need cash to buy them. I have been buying in Ackermans for years I have never receive such bad service and I'm so disappointed with their service.