Defect rings at exorbitant prices

My fiance bought me a beautiful engagement ring from Browns for an exorbitant amount of money. Within a year 6 diamonds have popped out and been lost. I have been told that it is a very delicate ring and I shouldn't even drive with my ring on. They have just reset the diamonds each time and refuse to accept that it is faulty. They refuse to guarantee their repairs or take responsibility for the faults. Every time has been a different diamond that has fallen out. Quite obviously a defect. Warn others about this as it will cost you dearly in the long run.