Bad warranty service

I took my car to Renault Paarden Eiland on 22 January to fix a rust spot still covered by the warranty period. They lost my information, did not return calls, made excuses and promises, did not deliver on the promises made time and again. I had to constantly phone them to ask for progress. Despite escalating to management who promised to resolve the issue, despite escalating this to the customer care management, my issue continued to receive poor attention... and it is a simple issue to have resolved. Eventually today, more than 1 month later, I have received confirmation of approval of the request. A service issue that their customer call centre told me takes 2 hours to get authorisation for. Unacceptable service!