Renault Northcliff rips off customers

First let me start off by saying Renault wanted to charge me R750!!! for new wiper blades. One can actually buy wiper blades for under a R100 at Midas- how they ******* their customers is ridiculous. I recently took my car in for it's yearly service. But because it was 13 days too late apparently after the service plan ended- Renault did not want to play and wanted to charge me over 3000 for a service- I can do a service anywhere else for cheaper. They did not even want to give me discount even though I bought the car there. I feel service should have been free since I have a 3 year maintenance plan and they car has only been serviced twice. No one should service their car there or buy parts at Renault Northcliff. Why would any customer stay with them?