From Consumer Wiki
Jewelry sale complaints should be made to the business involved. If the problem cannot be resolved, the consumer and the business may seek mediation through the Better Business Bureau. The consumer may have to resort to civil resolution, such as Small Claims Court.
The American Gem Society (AGS) is a nonprofit professional trade association of fine jewelers and jewelry suppliers operating in the U.S. and Canada. Will take complaints from consumers if jeweler is a member of AGS.
American Gem Society (AGS)
8881 West Sahara Avenue
Las Vegas, NV 89117
(702) 255-7420 Fax
The Jewelers Vigilance Committee will accept any type of jewelry complaint. Will advise consumers about jewelry markings and investigate violations against marketing, advertising and related jewelry industry laws. Consumers must submit their complaints in writing.
Jewelers Vigilance Committee
25 West 45th Street, Suite 1406
New York, NY 10036
(212) 997-2002- Tel
(800) JOI-NJVC [564-6582]
(212) 532-2217 Fax
JVC is headquartered in New York City. Normal business hours are 9am to 5pm, Monday through Friday (Eastern Time) excluding National Holidays