Horrible Ring Repairs on Brand new Ring

I bought an engagement ring on 11 November 2017 from Nwj Polokwane the ring was sent in for a size adjustment, when the ring came back after about a week My fiancée noticed that some of the diamonds ons the perimeter of the bigger stone shifted and that some of them where loose, we moved to Johannesburg in the mean time so I brought the ring in to Nwj the Glen for repairs. The lady told me that she'll send the ring size along with the ring incase the ring was a factory fault, they could provide a new one. After about 4 weeks the he ring came back in worse shape that we sent it in. The stones where shifted even more and some stones were still loose the ring looked terrible. The manager said she'll have to send it away again for repairs. We have been engaged for two months now and my fiancée has worn her ring for a week. How long wil we have to wait now and how wil we know that the ring comes back in a proper condition because clearly the head office where the ring is sent to for repairs, doesn't care for quality check or quality service. It's a shame really because the staff is excellent and extremely helpful just a pity the service from head office is of such a low class.