complaint

Good day, I bought shoes for my child at Canal Walk Cape Town in December, all to found when I was in Eastern Cape that the shoe size was incorrect was a size 12 instead of size 13 that I have requested on the day I bought the shoes. She did not try the shoes on when we got home as she tried them on at the store. She only ware the shoes on the 31 of December for like two hours and that's when she realize that it was not her size and she took them off and I took them back to the box. I then took the shoes to Promenade Mitchells Plain and they told me that they can not take the shoes back because the shoes were old, so I took the shoes back to were I bought them at Canal Walk and they told me the same thing that the shoes are old they can not take them back and they told me that they only take back the shoes when it's a factory fault?, They told me that it is stated on the slip that no returns ( Assuming that all the customers understand what is written on the Slip/ can read), Should they have explain to me the terms and conditions I should have made sure that she fit the shoes again at home and made sure that the size was correct. So what can I do now because am stuck with a pair of shoes...