Extremely arrogant and offensive tenant - how to deal?

[Chootar Laal]

What is the correct way to deal with a tenant that gets extremely offensive in both emails and in person? Basically 2 out of the 3 people in the apartment act this way, 1 is much much worse.

He has not physically threatened (as he understands the consequences) but speaks with a demeaning, condescending and hateful manner every time, on email and in person.

Apparently if there is an issue, like a broken toilet chain or broken blind, instead of fixing it the same day the tenants report it, I get to it within 2 days, maybe 3. There are 2 full bathrooms in the apartment. None of these issues have been an emergency. They think I should fix it right away as if I sit on the porch waiting for something to occur.

In fact there was an emergency issue, where an ice maker line busted at 10pm, and they decided to email me instead of calling me. They called me at 8am the following day, by then there was a lot of damage to the drywall in the unit below. But I never said anything to them about their carelessness and negligence.

They have a lease until 8/31 and I have their last month's rent and security deposit. But he threatens to leave the place before then and wants his last month's rent and full security deposit back.

Also, what are the guidelines for entering the apartment for an inspection as a landlord/property manager living next door? I live in Massachusetts.

His manner when addressing me disturbs me the most. But they all pay the rent on time.