They were demanding money again and threatening me.

Landlords can enter a tenant's property for a variety of reasons, including: Making repairs or replacements Responding to a tenant's request Removing unauthorized window coverings Preventing waste of utilities Changing filters, testing, or replacing smoke detector batteries Inspections Helping with an emergency inside the unit Posting a notice of eviction"Research your state laws because some of your comments indicate a lack of understanding of the landlord/tenant laws where you are operating (like threatening the tenants to keep the security deposit if they don't respond to you, I doubt that is actually a valid reason to keep their deposit, or evicting for late payments, or charging the tenants for your warranty repairs because you missed your 11 month inspection window which was your responsibility, and it looks like your lease says you can charge up to 18% interest for unpaid fees, is that actually legal?).

She has also threatened us!

@Jae Yoo you have a few options:1) Hire an attorney to write a threatening letter.

Yet for owners of rental SFRs, duplexes and condos—not to mention retail and restaurants—COVID-19 threatens to reduce landlords’ rental income, perhaps entirely.

FDCPA controls debt collection and makes sure that buyers  of defaulted debt don't threaten borrowers with violence , phone calls in the middle of the night and non-existent jail sentences for failure to repay.

They are threatening to sue to try and get something from you but most likely will not go through with it as you have no written contract in place and in california there is also no non-compete agreements.

But I will shine a light on the next threat that I hear about and name the person threatening.

And now, a Steve Martinez from their FL number called me to put someone named Cody on the line screamed at me, cursed me out and threatened me for speaking bad of them.  

Then one of their coaches threatened to back out but the student finally was able to get through to Tyler, they worked it out but now they need even more money for the contract extension.