Zales

My boyfriend bought my promise ring at zales for 2000 about a year ago. Within six months one diamond fell out so I went and bought the lifetime warranty and got it cleaned and fixed, I just noticed that my ring is missing two more diamonds!!!! This is the most annoying thing ever . Why do these diamonds not stay in ! Also, my annual check up for it was in January and we were In Texas for a couple weeks for a family reason so I missed the day, so I’m wondering if I have to re buy the lifetime warranty? Any advice would be greatly appreciated.