Global Vantage Phishing Scam Nationwide

My wife was contacted about 2 months ago by Global Vantage.

Their initial ploy was to say that she owed $750 on an American Express bill and they were trying to collect. They were relentless in trying to get any piece of information they could on her. She confirmed her name, that she had an AMEX card, and the last 4 digits of her Social Security number. THis was before she asked me about it. They did give a 866 number. Their accent was Indian and they even admitted that they were from India whether or not that was true. After this call, I started to try to get info from them but they did not divulge much. I mentioned that I would report them but that did not stop them. I called American Express and they do have a collection company called Gloabl Advantage but not Global Vantage. If these people contact you, do not tell them anything even what city you are in. I would report them to someone but American Express could care less about fraud and I do not know any government agency that would take my complaint seriously. Collectively, there are 6 people on this site that have complaints about Global Vantage and we have their phone number. Any ideas out there?

Marty
Laguna, California
U.S.A.