How to end Home Solicitation Calls?

I have a rental property in Katy, I have been receiving calls to purchase this property for YEARS. I’ve owned it for 8 years and have never put it on the market nor had any intention of selling. I have literally told these companies exactly that hundreds of times. But the calls keep coming. It’s difficult to track who’s calling as they never leave a company name only that they represent investors interested your property.

Recently they’ve upped their game by mailing pictures of my rental property to my home address. Which I find unnerving and overtly threatening. I’ve called them asking them to stop, and it just keeps coming. Six months ago I had my contact information removed from the property with the county, and still they keep calling.

I feel that asking them to stop and continuing to receive these solicitations is harassment and now crossing the boundaries into criminal. I’m preparing to call the Fort Bend County Sheriff and if possible seek legal advice. To either get it to stop or impose penalties.

Does anyone have experience of advice with this? And I use my number for work and get numerous calls from numbers not in my contacts, so that’s not an option.