Didn't answer. Never answer calls you don't recognize. If it's a legitimate caller, they will leave a voice mail. Sometimes companies are just collecting data to find out _when_ you are home and _when_ you answer the phone, so they can sell that info to other telemarketing companies.

is most likely a bug

Called said I'd been selected for a paid consumer survey, went right to try and schedual the appointment.
my paranoid self suspects a trap for debt collector or law trap