Car rental companies don't refund deposit back

I pre-booked a car to rent whilst in the UK from **** car rental at Casablanca airport at 6:30 pm. I expected they would have an office at the airport, but they didn't. I phoned them and they said told me to wait in the main car park and they will send someone to pick me up in 5 minutes. I had to phone them 3 times and waited over an hour before someone came. The driver drove me to their office which was about 5 miles away. When I went into their office there was a German family and Canadian couple complaining about things.

They wanted 17,000 dirhams as a deposit to rent a car for 4 days, I didn't have enough on my credit card so they said I could pay them 3,000 dirhams deposit plus 1,220 for for cost of rentaing vehicle, which they took from my debit card. I was at the office about one and half hours before they gave me a car which was old and had manual gears. By this time I was very tired and needed to drive to see wife for a suprise birthday which was over an hours drive away. They car had no fuel in the tank so I had to stop at a service station and paid 400 dirhams for fuel.By now it was dark and the engine warning light was staying on and there was a rattling noise coming from underneth the vehicle and the radio didn't work.

The next day I found out that one of the passenger doors wouldn't open. I phoned *** car rental company and they said to take the car back and they would give me another car. When I took the car back they could only replace it with the same model which was old and dented. I was not happy and asked to terminate the rental agreement, They said I was only entitled to a refund of 3,000 dirhams, so I agreed and they said the refund would go back into my bank within 48 hours. It's now been 3 weeks and I still haven't received my refund. I have contacted  *** car rental several times but they keep telling me it must be my bank.

I've contacted my bank and they said there are no problems with my bank and to get back in touch with the car rental company. The thing is, I rented another car from a different car rental company the next day at Casablanca airport because I needed a car and paid them 5,000 dirhams deposit, the car was great but I'm having the same problem getting my 5,000 dirhams back from them too. It's now been 8 days since returning the car and I still haven't received my deposit back. Does anyone have any idea what I can do to get my deposit's back from these car rental companies in Casablanca?