I received a call from this number and did not answer it. The Caller ID is "Starnet Inc Jac." There are various Goggle hits on "Starnet Inc Jac". Note that I am on the Federal Do Not Call List/
I know of 2 ways this scam can work. Both start with them asking for your credit card number and you giving it to them.
1) Legal. They send the $40 gift card. They sign you up for some sort of shopping club, with the membership fee charged to your credit card. It takes months for you to get the membership cancelled. The fee you pay is way more than the $40 card.
2) Illegal. They spend your credit card out to your limit or beyond. They never send you the gift card.