Chubb is taking me for a ride

I cancelled Chubb because the property belongs to my late mother. So because it was sold I canceled my account. Now Chubb has handed me over to NSF and is threatening to blacklist me. They say I owe them for removing a device in the property but when they handed me the letter of cancellation they said I owe them zero. I don’t believe I owe them because I don’t own the property and when they came to collect the device the house was not in my name and I didn’t ask them to collect it. They arranged with the new owners.