Payment Deduction

I hired a car in July 2017 and returned it in August 2017, everything was paid and the deduction went off in August for all the outstanding amounts. In January 2018 I receive an EMAIL stating that they will debit my account with the remaining outstanding amount for the vehicle returned in August 2017. I rep**** to the email asking why this is only been deducted now as I was under the impression that everything was deducted, they responded by sending me an invoice and not an explanation. Can't even action an email!! This is COMPLETELY unacceptable that you just want to debit my account, no explanation, no even a DAMN phone call to explain or heads-up. Not even an apology... Do you think I just have cash lying around in my account for you to debit??? 5 months later you want to come up with an outstanding amount and debit my account???? SORT THIS OUT ASAP, WRITE THE AMOUNT (If there's an outstanding amount) OFF COZ I AM NOT LIABLE FOR YOUR SILLYNESS AND HORRIBLE CUSTOMER SERVICE. Sort this out!!! Horrible Horrible Horribe - BUGET RENT A CAR SUCKS!! Will never use your services again....