The "law" does not impose any obligations on property managers; it is a contractual relationship, and the obligation(s) of the property manager are defined by the contract or agreement between them and the property owner. The property manager must do whatever the contract/agreement says they must--no more and no less. Therefore, you need to look to what the agreement between you and the property mangers was: if they failed to live up to what they agreed to do, you could sue them based on breach of contract (i.e. violating their obligations) and/or fraud (lying about what they could or would do) to recover any losses their failure(s) caused you.