You can put in a complaint with the Consumer Affairs Div. Housing. You can find the form on the web.

Pay the amount they say you are delinquent or you will be charged attorney fees, collection fees, etc. but continue to pursue the issue. If your state has an agency resp for adjudicating HOA complaints file a complaint with them. If not, you may have to take this to small claims court. Make certain you have documentation of proof of payment, i.e. cancelled checks together with copies of email and snail mail communications with the mgr, board and attorney. The fact that they are refusing to discuss this issue may also be a violation of your gov docs and state law. Check this out;you may be able to include that in your small claims case. In AZ a member has a right to be heard by the BOD when there is a dispute.  
 
In fact if you let the board know you are going to small claims they may drop the issue.

Mary is right. I've seen this many times before. Usually it's really because of bad accounting, not any malicious intent. 
 
- Pay the amount requested 
- Send a letter to the board explaining the situation 
- Attend your next board meeting and discuss the issue. Politely let them know that you intent to file suit if they don't address the issue. 
- if the issue is not addressed file a small claims complaint for the amount owed. 
 
Most important thing - keep an open mind when inspecting all documents provided to you. sometimes it's possible that the management company is right and we are the ones that made a mistake.

If you purchased your unit in May or June of 2010, you may want to review your real estate documents to make sure there was no hidden up-front HOD that was missed. This happened to me so I ended up paying the dues. Fortunately the late fee was waived due to first time condo buyer naiveté. Be sure to include your findings with your defense presentation.

1. Everyone is correct to tell you to pay the amount then I would request in writing a copy of your owner payment ledger since move in to see exactly what has been posted to your account.  
 
2. Depending on what accounting software they use they may post payments by check or moneyorder number so it will be easy to compare your method of payment to their postings. 
 
3. I would explain the situation and provide copies of the front and back of your cancelled checks, make sure you darken out your bank routing and acct. number since multiple people may view the documents. 
 
4. If you do have to file a claim against them ask the court to assign a mediator because this way they would be forced to speak with you and you can possible avoid legal fees.  
 
5. If you have to get an attorney, try the Legal Aid Society in your area. 
 
6. Document all communication, dates and times if possible as to who you spoke with regarding your account. 
 
7. Your HOA's attorney is aware of Fair Debt Collection laws, I am very surprised that they are not responding to your requests or providing answers to try to resolve this without it escalating legally. 
 
 
 
Good Luck and keep us posted!