Bad workmanship & Bad service

We bought a ring about 10 October 2015, we waited 3 weeks for it to be resized (as they forgot to send it in) upon return the ring was badly stained on the bottom and I sent it back once again, waited another 2 weeks, my mother went to collect the ring, as I was on honeymoon, when I took the ring out the bag 3 of the cz was out. I took it back and they gave me a new ring (sent it again to be re-sized) waited 2 weeks again. I collected it the last time the day before Christmas and today 28 December another stone is missing and the re-sizing line at the bottom looks like its cracked. Upon my return to the store they said they are unable to give me my money back as they don't have any cash in their store.