Avis refund not received.

I had a very good experience with Avis customer care but now I am having trouble getting my refundable deposit. I took the vehicle back on the 15th March and I still havent recieved my deposit. Someone called me and asked for my banking details I gave it to her. I still didn't receive my money. I received a SMS last week to to send my banking details again I did and still nothing happened. Yesterday I call Avis and I am told that they had a system glitch and payments didn't go through. This morning I get a notification on my phone that an amount of R225 has been paid to me instead of R2500. No one has called to explain to me. Does it take a month to receive a refund. I'm disappointed.