It sounds good to me; like Wild Flower points out, the people calling you Thursday wouldn't know anything if they weren't from SS. If you are still worried, I would ask the Thursday people how to know it's them, ask them something that is in your file that only you and SS would know? The name of your doctor? Something like that? But I don't think they'll ask you any more questions (they know your name, address, phone number, all "their" information they need), they want to "give" you something and I always listen to people who want to give me things, LOL.