Generally, people get the benefits and services they request from their HMOs. For more information call your company. If you don't do this you may not be reimbursed.
Some states have laws regarding appeals.
New York law is very specific and is explained in the pages on appeals. Check your plan booklet to see what rights you have to an appeal. But since your state may have specific laws regarding appeals, you may have even more rights than your plan describes. You may need to contact an attorney to understand what rights you have by law. Keep all correspondence.