Sams Club in Littleton, CO Sams Club is selling fake diamond earrings Littleton, Colorado

Buyer Beware!!! Sams Club in Littleton CO is selling fake diamond earrings and who knows what other type of fake jewelry they are selling!! My brother went there recently and purchased a pair of diamond earrings for his wife. His wife did not like the diamonds too much and so they took them back to the store trying to exchange to a better/more expensive pair and pay the difference. However, the sales person and the manager there immediately tested the diamonds and claimed they were fake diamonds. My brother was furious because he thought he had purchased a pair of real diamond earrings for his wife. They DID NOT test the diamonds when they sold them to him. My brother, being a guy and had not purchased diamonds before, didn't know the sales person was supposed to test the diamonds before he paid for them. The sales person claimed she tested the diamonds which she in fact did NOT do. So Sams Club sold a pair of fake diamond earrings which cost $399 plus tax to my brother. Now the manager there treated my brother like a criminal and totally believed his sales person's words. My brother asked that the matter be investigated further to see who is lying and asked them to view the security camera video tape which they have above the counter on that day to find out whether the sales person in fact tested the diamonds before she sold them to my brother, as the receipt shows the date and time of the purchase. However, the manager & the sales person there and Sams Club headquarter were totally rude and would not do anything else except to blame my brother. This would appear to me as if the manager and the sales persons there were into some kind of scam that they switch the diamonds before selling them to the consumers. Does anyone have any suggestions to help us get some help, from any organizations who can put pressure on Sams Club to investigate this matter further so that my brother can either get his money back or get a pair of real diamond earrings?