Misleading booking process from car Flexi and Euro car rentals

On 01/01/2019 my family decided to rent a car for the day and opted to look for the cheapest rental around. We used Car Flexi app and was redirected to Eurocar rental as the cheapest. On the site it said that there was an amount of +-R789 due for the day rental and we required to book with a card which we did. We entered the card details and an amount of +-R389 was deducted and we received confirmation of the booking. It further said that an amount of R400 was to be paid at the counter on collection of the rental and that there would bevno charge for cancellation. We arrived at Euro car and my brother in-law Anthony Kalie proceeded to complete the transaction as we planned a day trip out and he would drive the rental only to be informed that a R13000 deposit was required. We then asked as to the reason nothing of this appeared on the site or confirmation. We were informed that it was standard. When we asked as to the R389 deduction we were told that this was booking fees by Car Flexi and this should be sorted with them. We cancelled the booking and contacted Car Flexi only to be informed that this was not the case but that Eurocar hire needed to sort it out. Again I repeat on the website you book on there is no mention of huge deposit amounts It also says the is no booking fee for cancellation, this is only forced on you on collection of booked cars . now we out R389 because of the misleading info on the site used by Eurocar hire. When we asked about car Flexi we were informed at Eurocar that they don't use that site yet you are immediately redirected there when you search for cheap car rentals and they are truly not the cheapest