Air conditioning and bad mechanic problems

1996 Honda Accord 126,700 miles 4cl. My air conditioning had been blowing hot air whenever it was hot out, and blowing cold whenever the sun went down or it had been in the garage for a while. The mechanic I took it to replaced a fan, added some coolant and checked for leaks. When I got it back it was still not blowing cold air and there was a strong vibration coming from my engine that had not been there before. (I lifted the hood and the fans were turning on and off every four seconds which was making the entire engine vibrate) I took it back and they said it was a pressure problem related to a valve, they said they fixed it but when I went to pick it up, it was still not blowing cold. I left it there for one more day, and they said they fixed it again (for the third time). It was working fine for two days and then all of sudden was blowing humid hot air. It is now back at their service center for the fourth time. I am hoping that you can give me some insight as to what the problem might be, if it is normal to take FOUR tries to fix it, and what my options are as far as getting my money back so I can take it somewhere else to someone who knows what they are doing. Thank you in advance for you much needed advice.
~Truly Frustrated.