Poor manufacturing of an engagement ring

<p>I bought a Engagement ring from Browns as they are know to be the best. After the first day i felt that the Stone is loose. they said that i can bring the ring back for adjustments. A month or so later 2 small diamond fell out and the Big stone was loose again. They said that i can return it to them as they will replace the 2 lost small diamonds and that they will set all the diamonds and big stone again and to make sure everything is tight. They ensured me that it is fixed and will not happen again. And few months later (5Months from the date of purchase) another small diamond fell out and the big stone is loose again. I'm at the point of not knowing what to do as i paid a large amount for the ring and we really like the design.</p>