Poor service from Outsurance Supplier

A few weeks ago my car was in a minor accident (but still running fine) and had to be repaired by one of Outsurance's panel beaters in Somerset West. It was just a bumper repair with wheel alignment. I got the appointment for this week Monday so I left the car there first thing Monday morning. After not hearing back from them for 3 days I gave them a call to followup. They called back later and said the wrong bumper was ordered and will take another few days to get the right one. They said I can come collect the car and return again next Monday. I was inconvenienced for 4 days not having a vehicle to get to work and all that for nothing. It seems like Outsurance should do a quality check on their supplier who is obviously in a great position being one of few selected repair centers in the Hottentots Holland area but delivering poor service to their customers.