Unresolved query

The accounts department at Ampath is quick to send attorney letters if account is in arrears but if there is a credit due, they don't resolve queries promptly. There doesn't seem to be anyone that actually understands my account to provide a resolution. I am if my account is over paid as payments made doesn't reflect on my statement. The consultant who was supposed to resolve this matter, after a week, still doesnt have a cllue as to what my actual query is & how to resolve the issue!!!!!!