Unauthorized debit

Avis continues to debit my account R7000.00 long after I've returned the vehicle and the contract is closed and this is for the second time, now my account is on the minus. Honestly I dont understand how you people conduct business, I've sent several emails to you and still the matter is not resolved. What's worse you cant even get one of your agents to phone me back.

If this is not resolved by monday close of business I'm going to take legal action ***