No stock and no change given

Visited Builders Warehouse Rustenburg Sunday 30 June at 1pm. We were looking for a garden lantern to replace the one we bought from Builders previously. It took ages to get someone who was interested in helping us. Eventually we were told they were out of stock. We were desperate for lights in the garden, so we chose another style and said we would take two of them. Again a long wait, only to be told "no stock." We gave up and went to the tills with other stuff we needed. When we got to the front of the queue, we were told they would not accept cash at any till, as they had no change to give. Needless to say, we left our trolley right there and went home empty handed.