Distressing start to holiday

Three days before our holiday to france, Holiday Autos emailed me with regard to the booking I had made with them a week before. They confirmed the booking and issued the voucher, which I printed off ready to take to the Citer car rental at Marseille Airport. The day before we set off, there was another email saying that there was a problem and , despite the fact I had payed in full £801.87, I needed to contact them. When I phoned, Holiday Autos said there was nothing wrong and the booking was fine. This continued twice more, with the company each time saying that the booking was fine and there was nothing to worry about. I was worried, so I telephoned the desk at Citer to confirm they had the car and the booking and this was all confirmed.
We arrived at 6pm on 5th July only to find after waiting an hour at Citer that Holiday Auto`s had cancelled the booking whilst I was on the flight an hour before !
I had my parents in their 80`s and my two sons and husband standing waiting for the car hire. After an half an hour trying to get hold of someone at Holiday Auto`s, I managed to speak to someone who confirmed the car should never have been cancelled and assured me that there would be a refund and apology from the customer care team.
Citer managed to rent me a car for the same amount again( woman at desk confirmed that it was the same vehicle ) so all I could do was pay on my debit card again.

It has now been ttwo and a half weeks and I have not had my money from Holiday Autos refunded. I have contacted them so many times but the customer care team have not been in touch.
I find this absolutly disgraceful and would recommend that nobody uses this company. The price I had to pay again was the same as I had already paid to Holiday Auto`s so there is no saving by using them.
Take heed of my story as the whole experience has been awful with nothing resolved and no contact. You cannot contact customer care direct as there is no number so you just have to rely on the person picking up the call at Holiday Auto`s
It is really distressing.