I've been getting these calls for years on one of our office back-lines. Definitely isn't from Marriott corp. One time, out of boredom, I entertained one of the callers whilst simultaneously sending a few messages to friends and we traced the calls to a call center in St. Petersburg, FL. Fortunately they normally use the same area code + NPA, so we just blacklisted them and haven't heard from them since.

I fear all of the blacklists will soon be obsolete though. A few of the scammers are now using ANY random caller ID when calling people. This month I had two employees tell me they had someone call them & say they got a call from their #, legitimately, not some scammer trying to use that as a gateway into a sales pitch.