These are scammers who are trying to con you into having you allow them to charge your credit card $4.94 for a "small service, activation and handling fee" to "mail" you your $100 gift card. Of course, we all know it's a scam setup, and the only way to thwart them is to call them back and tie up the line with them for as long as you can by asking a bunch of silly questions. They won't hang up because they want to try to convince you they are legit. I had them on the phone for 20 minutes.
"Stonebridge Benefit Services" aka "Savings To Go" aka "Leisure Plus"- Total scam from some Indian phone call center - I gave them phoney cc number and the address and phone of the Chattanooga office of the FBI. They "muted" the cost of all the items and connected me to several phone based scams, each time asking for my CC number.