Why are the 3rd Party Providers allowed to exploit

I am very annoyed. I booked a call out with King Price today as the Geyser switch was broken. Excellent reception, call centre agent handled the call, progress excellently, that is the Insurance company and I am there client. A-call-away responded very swiftly and in no time the matter was resolved.<br> <br> Then what is the problem. I as the consumer am responsible for the payment of the Parts which I did via EFT. The 3rd Party Service Providers have got fixed rates that the Insurance pays them and that is negotiated. The replacement part - an Isolator breaker in DB (2 Buttons), was replaced at a WHOPPING R504.45 which I was liable for. This part to me at Plumstead Electrical as a cash client is R190. The Mark up is more than 200%. I spoke to Amy of A-call-away who advised me that I have the choice and do I want the part removed. None of the above, I just don't want to be exploited and ****** in daylight. I have got no choice but if I want t use the benefit of MY POLICY to use the appointed Service Provider. Everything gets regulated but the Man on the street always pays the price. Now i must find another insurer and I am happy where I am. You just don't win