Did not recognize no. so I didn't answer.  Caller did not leave message

Bill collections

This phone number has been calling me for 3 weeks without leaving any voicemails at all, sometimes even calling 2 or 3 times in a row. I answered so I could be prepared to block them. It's Spectrum calling to ask if you would like their services. I already have Spectrum, and when I told them that they told me to have a nice day and hung up. Very irritating.