quick to take money but refuse to refund

My husband bought a wedding ring from sterns in Alberton city about a week ago got home wanted to put the ring on and a stone was missing and not even in the box went back last Thursday was told they cant refund me as they have no money then my husband went back today as he was told to come back and they still dont have money went to the one in the Glen also told him sorry please come back another day as we have no money. This is the 2nd time we buy from Sterns and the stones fall out