Insufficient refund policy problem

Insufficient refund policy problem! I bought a pair of denims on 30/10/25 within a special of 2 for R220. (Discounted from R135 each). Price on til slip was thus R110 per pair. On wanting to wear the jeans out, I found a defect on the sewing of the denim, a hole near the zip. I was told at the Balfour Park Jhb store where I bought it, that they will only be giving R85 back. The special offer amount on slip is R110, which is what I paid for the item. I contacted their head office and this was the email response: Please note that we do sell rejects of name branded clothing, our prices allow for this.  With regards to the promotion of 2 for R220.00, that promotion is when you are taking 2 pairs, so when you are now only taking 1 pair, the pair that you keep the system automatically puts it back at the original sell price of R135.00 so, if you paid R220.00 and bring back 1 garment that will be R220.00 minus the sell price of R135.00 that leaves a balance of R85.00.   Same applies if you bring back both pairs of Jeans, you will be refunded R220.00 and when you purchase 1 pair of jeans after the refund you will be charged R135.00. ----‐--------------- To me, this is unacceptable nonsense and a way to swindle customers out of their refunds because they know they sell defective clothing. No matter the mechanics of a special offer, the amount indicated on the purchase slip of what was paid for an item should be what is refunded!