Excess refund not received

Upon collecting a booked hire car from Lanseria on Saturday 28 February 2015, an enormous amount of money was deducted from my bank account to the exact amount of R12,345.00. This was a complete surprise as there was no warning on my booking confirmation & the person at the counter did not show me anything nor did they warn me!! I did not even swipe my card!! I was then told it is a blocked transaction for excess & fuel which will be immediately refunded upon returning the vehicle the next day Sunday 01 March 2015. Bearing in mind I had paid already for the booking an amount of R2,117.52 - this amount was clearly visible on the booking. No mention of money that will be deducted from my account amounting to over R12,000!! (I am talking about twelve thousand three hundred and forty five Rand). I was told when I returned the vehicle that my money would be refunded by noon on Monday 02 March 2015. I am still waiting for my money, where is it & when will it be refunded? It is now 2 whole days later & I am beginning to think I have been ******!! I will be taking legal action if I do not get this money deposited back into my bank account within 24hrs from now.