AVIS is stilling my money

I booked in a car on the 13th July and R8808.23 was reserved by the company. On the 19 July R2414.40 was further reserved by the company in order for them to close the account. On the 27 July R11 897.14 was debited from my account by the same company which makes the company to sit with the balance of R23 119.77 in stance of R11897.14. I feel like the company was trying to rob me and I went to the branch and phoned the company's call centre and all I could hear was that it was the my bank's fault. My account is currently sitting on overdrawn balance and I am suffering charges because your company is taking money twice from my account. I do not have money lying in my account for charges that are being done by someone who did not do the work probably. I already have R 120.00 of unpaid charges and I am not sure of the charge of the overdrawn account. Somebody must take responsibility because this is not how the big car rental company like avis should operate. I am very disappointed.