Double debits

I have been very patient with this issue but now i have seriously come to the point where i do not know what to do. Avis has done this 3 times and the first time it was rectified and i was a happy customer again. This morning i woke to a message from my bank stating that my account is in excess, and i immediately knew it was Avis and then i go and check my account, R5889.19 has been debited off my account. I did not have that money available and besides why was i debited again?<br> Early last week an amount of R8900 was withheld from my account which was never agreed upon initially and i called Avis Durban and i was told it will be reversed. This week, still nothing was done. I then sent an e-mail to Deshegen the manager, who asked fror my card number and i sent it to him. Today, Avis runs a debit!!! What is going on? I still never received a difference from the two R7500 that were withheld by Avis in the previous months. I need this matter and my money ASAP AND I WANT AVIS TO PAY THE BANK CHARGESand on top of that Avis are messing up my account and CREDIT RATING. How am i going to get that back ???? How am i meant to survive with no money this weekend?