annoyed

I bought boots & Nike Topfor my son at Cross Trainer The Glen on the 21st March 2023, I went to Cross Trainer Trade route to credit it as my sister brough my son the same boots from the UK. I was told @ Cross trainer Trade route I can do an exchange but not a refund. No where on the receipt does it show no refunds and the consultant also never indicated anything. I cant be forced to keep something that I'm not going to use and if someone in the store dropped the ball how does it become my problem?