Sterns wedding rings are not value for money

My husband bought me a wedding ring from Sterns fourways on the 23rd of March 2022 valued at over R8000,last month the ring diamond fell off which does not make sense to as to how something so highly valued can deteriorate with these short times lines.I am disappointed in the quality of Sterns products and won't recommend that you waste your money at the rings are not value foe money.When I went in-store I received no assistance besides the fact that the ring may have factory fault and I have to pay for it to get it fixed as the warranty is six months which is not reasonable if the value is so significant.