"Go away, you are wasting our time we need to attend to the queue we cant help you. " manager - Consumer Complaint for PEP STORES

I went to PEP at Mphephu Plaza to change 6 items which were small sizes.All the things that i had bought initially costs 1200rand. Then i got 3 and the other 3 they were no sizes. I then asked the cashier(i have her pic and name) is it possible to change these three then i will go other pep stores to change the remaining and she said its possible. I then let her go on with the transaction. After she completed, she then told me to write my address and name at the back of the receipt and i told her isn't i need to use the receipt to other stores. And she said no its not possible. And i asked her why because i had asked her in the 1st place. She answered i didnt know you get change on the 3 items that i exchanged.she then called the supervisor /manager and the manager was so rough. She said there is nothing that we can do take those items you didnt change and make a plan somewhere and i said how with no receipt and she said you can keep them. And i told her i am changing they are small what i am supposed to do. I then asked them for a refund and she said its not possible dont waste our time take your things and go we have queue to attend to and she went her side office and closed the door. So what i am supposed to do because i am holding on things that my child can not fit. And i cant change them i dont have a receipt to change them in any store