Stihl blaming me and ignoring me.

I bought a brand-new machine, only for it to fail after a few hours, I was told it was basically my fault, after laying out extensive evidence, I was told that yes, I am right, and they will cover the cost, and from there on out, my emails have been ignored. So much for a grantee. This whole ordeal has been stretched over 5 months now. Highly disappointed.