hello, there is no problem with the cutting of these stones, if they were cut in any other way, you would not have the concave effect,we have sold thousands of similar stones to dealers all over the world with no complaints, we have also set many in gold rings, again without problem,
However, our sutomers satisfaction is our main priority, so of course if you would like to return these items for a refund or credit , please contact me again and I will email you the details you need.
Or if you would like us to set the stones in your designs, we would be happy to assist and at prices which would be much cheaper than you are currently paying(we only use 18K gold)
kind regards Jeff