Overcharge for a job not done

Last week I went to Supa Quick in Brentwoodpark to get new rubbers put on my cars exhaust pipe, 1st I waited for longer than an before they could help me, then they over charged me with this small job, so I paid them their R180 for some rubbers and to make a new mounting for it only to find out almost a week later, nothing has been done to the car, I had to take it to another exhaust shop for them to tell me it has NO rubbers in (after experiencing the same problem for almost a week), I am disgracefully disappointed in this kind of service for the money's worth.