Person keeps calling me; how do I stop it?

For about 4 months now I get calls from what sounds like an older Spanish speaking woman. I get about 5-10 calls a week. I've said "wrong number" countless times, I've screamed, cursed, threatened, you name it. Still won't stop calling me. I have this person on auto-reject on my phone, but it doesn't always work and I'll get voicemails occasionally. My phone provider says they can't do anything, and I'm not quite sure this is worth calling the police over. Any ideas would be greatly appreciated.