3mnths later.. Still no refund on car hire deposit

I used car hire from the end of September last year into the middle of October 2015. I was informed that the money will be refunded to me within a few days of returning the car. After waiting a month I decided to call MiWay and they said that the money was refunded and should check my account. I explained that I have been checking my account and it wasn't done so they decided to follow up with Avis and told me the money will be refunded within 48 hours however this was not done. I called in again last month querying my refundable deposit and once again they informed me that it will be refunded within 48 hours. I've been checking ever since and still the money has not been refunded. I did email the guy I spoke to who told me that I should check my account within 48 hours however I am still waiting for his response. I am tired of the empty promises. Can someone call me and let me know when the money will ACTUALLY be refunded and can you guys at least follow up to make sure it has been refunded!! I shouldn't have to be the one that keeps calling you guys to follow up on the same query twice.