Does not take responsibility - blames the customer

HONDA WEST RAND. I am so upset and disappointed in your service. A loyal customer for over 5 years. I phoned and told you about what happened to my car, that two days after my service a few weeks ago, we were driving to KZN and there was a loud noise underneath my car. We had to pull off the highway as part of the plastic cover under my car had come off and was hanging down. Now that I am back in JHB, I phone yesterday and was met with a "you drove over a bumpy road" and today I was told this same thing again and that I now have 4000km more on my clock now since my service. Yes I do - and you refuse to take responsibility that your technicians clearly did not fasten the cover properly after my service and now my cover is damaged and you want R1600 to fix it. My car has 84000km on the clock and I have NEVER had an issue with the cover. But the blame is pinned on me. I actually cannot wait to sell my car - I am tired of dealing with Honda. I pay thousands for services with you and this is what I get and I get no help from you when something is wrong with my car and I explained what happened and just get the blame. I am just so frustrated. My car is paid off and I am going to sell as I cannot actually deal with you.