Answering machine picked up this call but caller left no message.

Keeps calling the house phone for my father about some kind of survey. Call before last, I asked to have our number removed. Called again twice today. Answered again and asked to be removed. Caller then said "His opinions are highly valued". To which I stated that had nothing to do with what I just asked him to do. Caller just hung up. This number has called 7 times in two days.

Do a search on call blocking devices and phones.If its a cell phone, there are free call blocking apps out there including trac & straight talk.
http://800notes.com/forum/ta-5d4e343675a5629/call-blocking-devices

Keeps calling wifes cell phone, no answer on call back. FBI family member will be notified..