AVIS on rampage with my bank account

Good Day<br> <br> I rented a car at AVIS, car registration DJ12KJ GP on the 16th June I returned the car on Friday last week. on Saturday I noticed that AVIS has debited my account AGAIN....and it has now put my account in NEGATIVE... which is affecting my credit scoring with my bank. Please assist me to ask AVIS to reverse or release my funds. I am very angry.... because my other debit orders could not go through because of AVIS. I need this matter sorted out TODAY..... my bank is on my case with this Negative balance.