Sentry Management — won't do their job...

I am trying to buy a property, and Sentry is the Mgmt Co for the HOA. Fannie Mae requires that a form be filled out by them, and they are refusing to sign it, therefore I my loan is at a dead standstill! Worse yet, the seller is about to lose it in foreclosure, but they do not care. We are talking about TWO QUESTIONS they won't bother to answer. They keep trying to blame it on another company they pay to fill out the forms for them called Condocerts; but if they hired them, then they should be instructing them to fill the damn forms out so the owners can sell their properties! They are going to hold up anyone that wants to purchase a property in any of their communities getting a mortgage now...it's totally unbelievable!!!