Terrible Managing Agents

Absolutely terrible experience dealing with this company. They are apparently the managing agents on our Home Owners Association but fail to give any feedback on reasons for backdating a levy increase for 11 months with absolutely no communication to any members. We are in the process of selling and they will not sign off the sale until we have paid this "arrears" amount, even though my current statement of account reflects a NIL amount due to them. Requests for the communication of this increase to the members, list of committee members, minutes of meetings, financials are all completely ignored and all we are told is this is an estimated levy increase that will be backdated until March 2023.