New landlord, has NOT contacted tennants what is the law about this?

Why didn't the previous owners/landlords tell you who to contact now? Easy for them to say it's not their problem anymore. It is their obligation to notify the tenants of the change of ownership in the property. Call them again. Assuming you were paying them the rent directly. You should pay the rent on time as you have done before even if there are maintenance issues that require attention.

It's really none of your business who owns the building in which you rent. You should continue paying the rent as always, unless officially directed otherwise. The fact that they didn't tell you to pay someone different isn't your problem - it's between the buyer and seller.

The law is you hold onto the rent and pay it when they DO contact you.