No Refund

I hired a car on the 13th of May and returned it on Monday the 18th of May. Upon collecting I used my chip debit card. Till today the money that Avis held on my card (about R2900) is still hanging there yet they deducted the R1600 that was due to them so my account is now sitting on a negative balance and the R2900 is still showing as \waiting for authorisation". I called the customer services yesterday and the lady said the money doesn't release automatically because it's a debit card but she has sent some automated email for them to release the money. Still waiting for my money. And I wish to know exactly if I hadn't called was she going to send that email? So unprofessional. Today is the 28th. Exactly 10 days after I returned the car. """