Un know number

Said "This is Dan from (something like cultured pearls or ?).net. I had to ask him 3 times what he said and it was like a recording saying the same thing 3 times and I still could not understand what he was saying and since he wasn't willing to slow down and just tell me who he was calling from - I hung up.

keeps calling back but does not say a word now.  This is harassing.