Service that doesn't deliver - Referred by Audi

About a week ago we called Audi Claremont to find out if they can install Cruise Control into our vehicle. They referred us to Claremont Fitment Center to do the installation. We were instructed to book at least 2 days in advance so that they can source the part. We booked it a week before. Today, the day of installation, I arrived. They checked the car and told me its a day procedure and I will have the car by the end of the day. I was getting ready to leave with the driver when they notified me that the part will only be here tomorrow. I restructured my entire week just to have the day free today to drop off the car and not have the need to use it today. And now they say it cannot be done today. They offered for me to bring it in on a Saturday, the day I get to spend we my kids taking them out and about and the one day in the week I can go to the bank and get groceries, etc done, I must work around their schedule - Unacceptable! I would never refer Claremont Fitment Center to anyone. Absolutely pathetic service! It's too late for an apology and an apology is is not going to fix this, neither is it going to install the parts timelessly without inconveniencing me.