New property management client: "We dont have to pay the rent on time, and we dont have to talk to you"

Interestingly, we signed up a new property management client recently, who then notified their tenants in writing and verbally that we were taking over the management of the property. We also notified the tenants in writing and verbally. Somehow these tenants, from Nigeria, feel that they can intimidate us, like they had the owners (who live 1000 miles away) and tell us that they do not have to pay the rent, or listen us at all. Either these folks like pretending reality has no impact on them, or they like hitting a brick wall...

Some background: these tenants have been paying the rent late (no sooner than the 20th of the month for the entire tenancy to date. They agree to have contractors come to make needed repairs and then are not at home, and the owner gets the bill for the plumber, carpenter, electrician, etc. for having shown up but not having gained access to the property. The tenants also yell at the owners, and now at my staff, for their lack of professionalism in wanting to collect the rent on time. Today I received the calls from two of them, all family, saying they need not work with us, and have no intention of paying the rent at this time.

They are now on a month to month tenancy, with the year lease having reverted to that as of October 31.

Seems I have to go there tomorrow, enter the premises for an announced and expected inspection, and wait until I collect the rent. Of course, I will have assistance with me, and that assistance will double as witnesses.

Fortunately for our client, we are not so easily intimidated... if we do not get the rent on time, seems we may be serving up notice for vacating the premises unless these people get real...

What are your thoughts?