Shocking VW ethics

This is an example of very poor ethics by a large company. In good faith I paid a very high price to extend my maintenance plan with VW for 2 years. I was assured it would give me peace of mind and worry free use of my car for another two years. VWs behaviour for a simple wear and tear claim shows this to be very far from the truth. I have VW Golf and have been the owner of multiple golfs for the past 30 years. I am what you call a loyal customer. On my current golf as mentioned I have extended my maintenance plan. Which specifically covers Wear and Tear. The knob of my cars air vent has come off and fallen apart owing to use and wear and tear. They are claiming it is broken and cosmetic and therefore will not replace it. It has never been abused and has come apart owing to wear and tear. It is surely not cosmetic as it is a functional piece which can no longer be used. I am shocked at the cheap ********* nature of VW and of their refusal to honour their plan and their refusal to let me speak to the senior consultant who made the decision. They have closed the conversation and matter one sidedly like a parent punishing a child. This is a very poor way to represent your brand and to treat a long term customer.