I want my money back: NWJ's gold holds no value

In 2008, I bought a 9ct Gold Large Hollow Flat Cross pendant from NWJ. At the time it was valued at R13 720.

In 2017 I tried to sell that cross and was told by a jeweller it was not real gold and had no value. I went back to NWJ and they sent the cross off for testing and came back with a letter stating the cross was 9ct gold and the new value of it was R19 980.

It is 2019 and I have tried again to sell my cross to two different jewellers and both said it failed the gold test and was of no value except what is on the paper. I have no interest in keeping this cross that only has value on paper but is worthless when trying to sell it.

How can NWJ say the cross is worth this amount and I am sure more now when no other accredited jewellery store will take it. What good is a piece of paper?

I feel as if I have been duped by NWJ.