worthless undervalued white gold engagement ring

I have bought a 9CT white gold with 0.16 certified diamonds engagment ring that was on special, its was marked @R5000 But the person that sold it to me said its valued at @R10 000 and I will get an evaluation certificate saying that its values at R10 000, i did get the certification as promised.

Unfortunately my parter and I and no longer together and I have no use for the ring..... i took it to 4 different jewelers to sell the ring as i no longe have use for it..... all of the barely offered me a thousand rand for the ring even after I showed the the evaluation certificate from NWJ which said R 10 0000....

I feel ********** coz I spent my hard earned money to buy that ring and if 4 different jewelers are barely offering me a R1000 even with official documenting from NWJ then definetly somthing is wrong....

I would like my money for what I have paid for the ring coz currently it it worthless....

I want a refund.