Sterns - petrifying bad customer service

I looked at an engagement ring online and went to Sterns in Tygervalley on Saturday the 19th of July. Lady assisted me by ordering the ring from one of the other branches. She told me that the ring would arrive beginning of the next week and she would send it for resizing as I informed her I needed the ring before or on Saturday morning. She assured me it would be ready by either Thursday or Friday. Feeling a huge wave of relief I enjoyed my weekend. By Tuesday I hadn't heard anything back from Sterns and it was starting to concern me. I gave them a call and they informed me the ring had arrived, but it has not been sent for resizing. Neither has anything been done to my TFG account in regard to billing. The new lady that I called on Tuesday informed me the ring needs to be paid before it can be resized, which is not a problem, but why did no one tell me on Saturday? Why did Sterns not call me when the ring arrived? They knew this was very urgent and told me everything would be done in time. Now after paying for the ring, they don't have the new size that it should be made because the lady never kept the details anywhere on the 19th. Now I have to go into the store for a 3rd time before actually going to pick up the ring. I can't get the ring in time for my planned event on Saturday and have to make new arrangements which will not only take more of my time but also my money but also cause me more stress. This has honestly been the worst customer service I have received in such a long time, and it is for something that is quite a big moment in a person's life. The worst part is the nonchalant behavior of their staff. They didn't even apologise or try to meet me halfway with arrangements for the resizing.