Understandably, you need a working mailbox and one that looks nice. Your first step is to reach out to your association to see what is going on. Start with a call and then follow up in writing. If you do not get a response, try a second time, again in writing, but this time by certified mail, return receipt requested. You should also attend the next board meeting and politely try to find out what is going on. Make sure to take good notes about all of the steps you have taken.