No reply to my emails

I keep receiving a statement from Drain Surgeon even though I have paid in full every time I made use of their services. I rep**** to the lady that sends me the statement to enquire why I am receiving it, to which she does not reply. I also sent this email with the statement to the main email address on the drain surgeon website, and still no one replies. I work in a call centre and cannot be on the phone and I just need assistance via email but Drain Surgeon just ignores my emails.