Very dissapointing service

My fiance bought my White Gold and Diamonds ring at the store in Mokopane in December when he was promised that he will receive the certificate in January. When he went to the store in January he was told that the lady never requested the certificate and she is on maternity leave. The lady that was assisting him at that stage promised that she would sort it out and he would get the certificate soon. We are approacing end of February alreadu and until today no has contacted us. No certificate was received and it make one wonder if the ring we purchased is really worth the small fortune that was spent. I need the certificate for insurance purposes. I am very disgusted and disappointed!