harassment by repeated phone calling even after being told do not call again

These people call repeatedly.  Sometimes as often as three time a day even though I have held on to talk to a person to tell them to stop.  One of the times I did this, asking how to get them to stop calling, their response was
vulgar and not fit for repeating.  Is there anything that can be done?   My husband is ill and recovering from surgery and these calls are a particular harassment.