I have had the car in for service several times due to defrost issues. The garage has had the car a total of a day and a half just this time to replace the defrost gear system. Is this an acceptable amount of time for this repair? They claimed to have repaired it already then said they had changed a dirty air filter and assumed it fixed the problem. I have owned the car just over a month and the garage has had it in total 3 or 4 full work days now post certification. The defrost has never worked. Any advice for me would be greatly appreciated.