Second time I receive a demand letter before an account

<p>ER Consulting INC/Dr Holt and Partners: There is no propper management of accounts, meaning no Credit Contol, account are not even sent to the medical aid but the account informs you that the saving is depleted with a 2016 date but its a 2017 service account and this is the second time where I receive a overdue notice before an account. How are you still in business???</p>