I bought my Mercedes-Benz car less than a year ago brand new from a local dealer. One of the volume buttons on the steering wheel developed some sort of an issue. IT seems that a spring or whatever is underneath it snapped (that’s my guess) so when the button is pressed it is not bouncing back.

I visited the dealership and asked to have it fixed. While I was waiting a member of staff examined it and came back saying that they thought something had been spilt and that was the reason though they could not present any evidence of it. As it was outside influence they refused to fix it under the warranty. What are my options?