There are so many of them present in the Sinaiyah area. Suggest, you pay a visit these garages with your car and let them give an estimate and the number of days they need. While they are having a look at the car, you can carry out a visual inspection of the garage and see the work that's being done on the cars present. The estimate will vary from garage to garage. You can then make up your mind. Needless to say, you will need a permission from the police for repainting the car before you can put it in any garage. No garage will accept your car without this permission letter.
From experience, let me tell you no garage meets its time deadline. Keep pushing the garage in-charge over his phone now and then and if possible, just drop in on one of the days to inspect the work.