Call to cell - left no msg

I received 2 calls today from this number.  Whoever it was did not leave a message.  I took a chance and called it back.  I heard a garbled recording stating that the survey I was calling about had been closed.  I blocked this number on my phone.

Just received a call by this number. No message. Since another poster said they called back and got a survey, I'll block this number.

I received a call by this number. No message.

Same.  Call.  No message.