White gold turning yellow for the 3rd time!!!

Good Morning, So herewith my story...

My fiancè purchased a "white gold" engagement ring last year around July but he only asked me in October. But anyway... I sent in the ring to get it resized and from there on I started wearing it. I don't sleep with it on, I don't wash my hand with it on and so forth because I don't want to damage the ring.

In July it started turning yellow. First I thought it was just wear and tear and sent my ring in to get it plated again because that is what the shop in Hartbee****rt said I must do.

The lady there booked it in around the 9th of July and on the 13th of July I got it back from the workshop. Then on the 30th of July I had to send it in again because it was yellow again.

First the lady said to my fiancè that he must drive to Brits and send it in there because they send it to a different workshop. But this is not our problem so he said the shop in Hartbee****rt must send it to them because it is there product that is in defect.

I got my ring back on the 4th of August and now it is yellow AGAIN.

It is not yellow on the inside of the ring which is touching my skin so it means that there is no reaction to my skin that might make the ring yellow. And now you can even see the piece where they had to enlarge my ring.

This is unacceptable.

I can't carry on like this with the back and forth and now with my wedding fast approaching I wanted to add a wedding band but if this is the case why even bother purchasing one from American Swiss.