Diamond falls our hour after engagement

1 hour after engagement the diamond fell out. Luckily we found the diamond and took the ring back a day later. We then got a new ring, paid for the upgrade of a better diamond, and twice the clasp is broken, it got sent back for repair but guess what...they didn’t repair it and tried to convince me that it was fine. They now say they will repair it again. I want a refund. I don’t want my browns ring I have lost total trust in the company. I want a refund.