If a garage hasn't repaired a car, you should give the garage a chance to rectify their mistakes and fix the car properly. If they refuse or are unable to fix the car, or they refuse to acknowledge that there is a problem with their workmanship, then get a second opinion from another garage. If the second opinion finds that there are still problems with the car, you can go back to the original garage to correct the problem. You could get the car fixed at another garage and attempt to claim the costs back from the garage. But if you get the car fixed elsewhere before giving the garage a chance to put the fault right, you won't be able to reclaim those costs. Find out if the garage is a member of a trade association - they often have their own dispute resolution service.