Over promise & under deliver

I am so incredibly unhappy with the service I have received from NWJ, my husband bought me a silver ring and the Centurion store informed him that we would be able to resize it. I handed the ring into the Rosebank mall on the 11th of January. I was called today to say my ring was ready. When I got here they informed me that they are not able to resize it. Sybil the lady helping me in Rosebank, had such a chip in her shoulder and I had to become angry. She has absolutely no customer service experience. She is rude and and kept arguing with me. I am now trying to get a refund, and it is a huge issue. She will not refund me as she has no money in her till. I WILL NEVER SHOP HERE AGAIN!!!!