657-202-6637(Unknown Name of course!). Possibly connected to 619-798-9835(read AT&T...but not). AT&T would never ask for SSN or credit card info!!! These are scammers. Per AT&T employees (friends) the company would use 800 or 866 area codes, not city area codes. The scammers use different area codes/phone numbers from all over.
If in doubt, call AT&T and question a number that keeps calling.