Another day needed for what???

I am a driving instructor and depend on my car for my income. I am a client for a while with Car Service City Durbanville. In the beginning I received very good service, friendly people and very helpful - sometimes on short notice they assisted me. All of that had changed for the worst. The 5th July I complained about a noise on the wheels if turning sharp, they only rotated the tyres whilst I had it done about 2 weeks prior to this, A oil leak was discovered which was fixed. On the 9th I took the car into a fitment centre because of the noise on the wheels and they told me there is a oil leak which needs to be fixed first because it damage the rubber. I had the engine cleaned first to determine if it was the original leak that CSC fixed, Was told to leave the car there for a full day (no income for me then), After that day i was told that it is a different oil leak and I will have to book the car in again for a full day since it there is oil on the timing belt then that must be replace as well. Again a full day taken off and again loosing another full days income. A client of mine called to say she booked her drivers for this morning at 9h00 which ment I would be done by 10h00. I sent Robert a mail confirming my late arrival due to the drivers test. He then replied that it is cutting it fine which I fully understand. I then sent Robert a follow up mail asking him to do his best to get the car done by end of the day and if not to keep me posted, could arrange for students to move their appointments for tomorrow to a little later, I also asked for the indicator stalk to be replaced which he ordered after my previous visit. Today only the indicator stalk was replaced and I was told to bring the car in again for a full day to fix the oil leak. When I asked him why he did not call me to say that the car will not be ready today than I could have move everybody a little later tomorrow. His comment is that he misunderstood my mail.