For about the past 4 days we keep getting calls from this number. They do not leave a message and if I answer the phone, they hang up immediately. Caller name is listed as Unknown.

same here. very annoying.

called left no message so called back got voice mail said they were company doing follow up call to see how was treated when was at car dealership.  Said company name was Advantage Plus on voice message but was not able to leave a message myself.  Think that this company needs to change its practice and not just hang up they should leave a short message should they get answer machine or voice mail.  So Advantage Plus hear that dont just hang up when you call a person that is not good business for a company that does follow up on customer satisfaction with a prior company,,,,,,

Glad you said who they were because I do Not answer numbers I don't recognize.  Advantage Plus, I have that from when I bought my new car.  They need to at least leave a message.  I was wondering who had both my phone numbers.  Thanks again.  I may answer them next time so they will stop calling.

Yes, I had my car serviced at my KIA dealer and this number called me to do a customer service survey.