Will Not Take my Number off their list

I have received repeated calls from a 303.601.3390 & 303.601.6867 company that has something to do with Solar.  They have said they are not selling anything.  This has been going on for months.  I continue to ask them to delete my phone number from their call list.  I have resorted to yelling and swearing at this Indian call center. They are relentless!  They will not accept my responses to their call.  They are very argumentative with me and I continue to get calls despite my straight request to be removed.  I have filled a complaint with the FCC.  I will continue to gather their vanity numbers and turn them in, until they stop calling me.  Hopefully someone can get to the bottom of who this entity is and pull their telecommunications line.