I called 636-223-8467 back from a land line. The recording said they are "Merits Customer Experience" doing customer surveys about products and services. They do ffer an 800 number to be put on their 'Do not Call List'. The 'Opt Out' registration does not cover surveys if they aren't selling anything.
This call came in late on a Monday night with an ID of "National."
I believe this is a company called Maritz CX (Customer eXperience) and their Support Number is 866.794.4785.
Didn't answer. Called the number back. Got an automated message. Appear to be a customer satisfaction that is subcontracted to get customer feedback. Didn't take the survey, just listened to the recording and hung up.