Horrible customer service at Auto Magic Centurion

I am currently receiving bad service at Auto Magic Centurion. I brought my car in for repairs on 26 April for a minor dent on the boot and rear bumper. They promised me they would be done on the 21st May but they are still not till today. They didn't even bother to inform me they forsee the repairs to be longer than predicted. I had to call them on the day I was supposed to fetch my car find this out. It actually took me 3 phone calls to receive my feedback as they promised to call me back with the feedback but didn't. They moved the date to Wednesday, 23rd. Same story happened. I call to check if they are done and they confirmed they are done; however the car just needs final quality checks and it will be done by end of business. It still took me a couple of phone calls and messages to get this information. The date was moved to the 24th then boom, they tell me the bumper needs to be replaced instead of being repaired and it will take longer to get my car back. When I took this car in I specifically asked them if they were sure they could fix the torn bumper and they arrogantly said yes. They always promise to call me with information on the progress of my car but never do. If I don't call them about 5 times I won't get any feedback. To this day I have no clue when I'll be getting my car back as they haven't gotten back to me after I called them a couple of times on Friday. I just don't understand why I have to go through so much to get feedback on my car. How long does it take to replace a boot and bumper? I wish I had taken my car else where, their customer service is really frustrating.