Product unsatisfactory

I would like to put in a complaint against American Swiss Nelspruit Illanga mall. I bought my wifes wedding ring by them in May last year, in October last year we took the ring back due to the stones that began to fall out, they sent it away for repairs, after 3 weeks we received it back, they failed to supply us with the repair receipt, February this year the stones started falling out again, today my sister in law took the ring back to them and the lady working there said that if you dont have the repairs receipt they wont be able to help us, i gave her my name and she "checked" on her system then claiming that they do not have anything on their system regarding the matter. She called my back a few minutes later and said that her Manager said that we are going to have to pay for the repairs if we send it back again. This is completely unacceptable. The system that they use are obviously not effective and it should be changed. We paid alot of money for a product that failed twice in 9 months, in the first 6 months " which they claimed is their warranty period" some of the stones fell out, by receiving it back after 3 weeks it should be new, right? Then the stones fell out again and they want me to pay for the repairs. Not going to happen.