Avis to pay deposit back

I hired a car in April. Paid for the car booking as well as a deposit of R2800 and was told that I would get my deposit after 30 days. Late May called them and they said payment will be made after 30 working days. I made the calculations my side and 30 working days ended 11 June from the day i returned the car. Today is 21 June & i've been calling them since 11 June. Emailed them as well and they told me a reversal was made. I emailed them back to tell them my bank statement does not show any payment. They refuse to show me proof for the payment.