Ribbons Office National

Two weeks ago I visited Office National Units K13-K18, Okavango Park, Kenwil Drive, Okavango Junction. I bought a few items, did a card payment. I left. +- 12 days later I found there a problem with one of the items (stapler). On 02 June 2020 I took it back, explained to cashier what my problem was. She immediately noticed there's a problem. She went to the isle where the item was. She read and explained to me (according to instructions it is suppose to staple 20 pages, it couldn't even stapled 5 pages). Then she went to another cashier which took me to the isle again (didn't even know where the item was) I pointed it out to her. She immediately told me she wont be able to refund or fix the problem because I don't have a cash slip or the box that it was purchased in. I was very upset then she said she'll go ask the manager. She came back and just said the manager said no. I even suggested to get proof from the bank, asked to check on their system, but their No was No! She told me they have lots of sales daily, I do understand, but not every person bought what I bought that day. My problem is WHO KEEPS A SLIP OR A BOX if no one tells you to do so??? HOW WAS I SUPPOSE TO KNOW IT WILL ONLY LAST FOR TWO WEES THEN IT BREAKS??? I was so upset and just broke it further and threw it right there in front of that shop. My money is wasted, but i will never put my feet there again.