Bad client service

I took my car to the panel beater to get if fixed on the 10th of August bust since then my car is not fixed,. Mind you it only the bumper that need to be fixed nothing more, the sad part is that they don't update me of anything I have to call them almost everyday then they will tell me stories, that there is a part that is short and there are waiting for it but when I brought the car to them, they said they have ordered everything and my car was going to be fixed within 3 weeks, and now it been a month and 12 days they are telling me different stories, this is really inconvenient for me because I am using my car to get to work I am angry I am frustrated and I want my car whether fixed or not.