Card Member Services This company promises to reduce my interest rates on my credit cards Gulfport Mississippi

A company going by the name of "Card Member Services" contacted me today offering to reduce my interest debt on my credit cards by as much as 2/3rds.  It was a man with an Indian accent, but he spoke perfect English.  He wanted my credit card number on the card i used with the highest amouint of debt on

I told him I thought he was running a scam,  and I asked him to send me paperwork from his compny so I could read all the details about his offer.  He ignored me and kept on fast talking me.  Finally I told him I was hanging up on him and I did.  I do not know what information he has on me, but I am worried about what he might d or has already done.. 

I am not sure of the location of this company, but their phone number carries a local area code on the Gulfport/Biloxi Mississippi Gulf Coast. Sometime during the call he asked for the name of one of my credit cards and I advised him of a BarclayCard Visa and the expiration date.  However, I did not give him the number of the card.