Unhappy customer poor service

I went to Rage, Protea Gardens were firstly they are short staffed, with little assistance they gave me a shoe size that I didn't now request for, they didn't not follow instructions and did not check it properly. I realized their mistake when I got home. Today am returning the shoes they tell me that my shoe size is out of stock and they can't exchange it for me and because it was on sale they can not do anything about it. I asked if they could call other stores to check if they have and reserve it for me, I was told they not allowed to do that also.... am not happy about the service received 😒. It is poor service to a customer after debating with them they eventually offering a gift card...