Brand new product won't be exchanged for different size

I received a black chino as a gift from my wife earlier this year. I haven't opened it until 2 weeks ago and noticed it was the incorrect size.

I've been to store to return it ( product not been worn and labels are still attached), called in to the call Centre and was informed that after seasonal sales products are allocated new barcodes, hence 'delisting' the product making them worth R0,01.

They were unable to assist but informed me that I can buy a 'new' one for R350.