Called and left no msg

Left no number. Called back & was a solar company message. Instructed to dial 2 to be removed from list which I did.

Call came through 9am. Answered call thinking it was someone else returning an earlier message.
The moment I answered, the other side immediately disconnected.  Uncertain what nonsense they are up to, only conclusion I can arrive at is that they are fising for good number to then sell off to other POS scammed once verified. I suggest you all block this, and whatever other 6 numbers they will undoubtedly robo dial with.