Refund counter, Greenstone - rude, disregard for elderly, completely unhelpful

My mother in law bought me a pair of trousers for my birthday at the Greenstone branch. But the waist was wrong. She exchanged it at her local branch Atlasville. Waist is right but the design is so bad, the legs are impossibly skinny and thus disproportionate to the size. She tried to exchange them for a refund or something else at the Greenstone branch. Of course, Atlasville took her original receipt and left her only with the exchange receipt.

The refunds counter at Greenstone was horrible. Staff was rude, unfriendly. They kept my mom in law (70 years old) standing and waiting for there for just shy of half an hour. They first refused to help, then got a manager who was willing to give a gift card for the amount, then another staff member came and refused even to do that. Verdict - she has to go back to Atlasville and beg them for a refund. Couldn't they have just said this in the beginning? Why did none of them know what to do? And how little do they care about the elderly, to keep someone like that waiting standing for almost half an hour?

While she goes back to her local branch to try again, I've asked her - whatever she does - assuming she gets the refund, she must spend the money anywhere except this dreadful company.