National Action Financial Services Harassing phone calls asking for a stranger after told no one here by that name over and over Williamsville New York

National Action Financial Services keeps on ignoring the laws and continues to harass me on the telephone. They've been asking for a stranger and refuse to listen after repeatedly telling them that no one is here by that name and to stop calling this number. One call even consisted of a woman using profane spanish to me.
I was appalled and again told them not to call ever again.

They continue calling and have left a handful of messages asking for the same person since then.
I have told them not to call many times.
What can I do about this harassment without having to change my phone number?

Looks at paper
Austin, TX, Texas
U.S.A.