They mostly call during the day or early evening.

...does not leave message, but calls three times each day.

want to stop these calls

Stop all the phone call.  I don't know this phone number.

If this is March of Dimes (which I believe), it's a shame--we may eventually have to outlaw phone charities in this country, if this type of disruptive behvaior keeps happening.

By the way, I DID call them back before looking them up on this site a month ago, AND I pressed '1' to remove us from their call list, and we started getting calls all week this week again.

So, I don't know if that works at all, but maybe sometimes...