5,000 km and dead

[macca]

The problem will be proof of what happened and why, that has to be understandable and rock solid with clear cut processes leading to the outcome.
Any questions or variables to the evidence offered and your case is cut off at the knees.
It could have been this or that and there goes your case.

Years ago I had a Ford diesel work van that a local dealer reconditioned the motor, it failed and it turned out to be a broken bottom ring.
At the time Ford had lifetime warrantee on their repairs but the fine print said it only covered lubricated parts.
Ford said a ring was not lubricated!
The head of mechanics at our local TAFE was an acquaintance, I spoke to him about it.
He wrote a letter quoting Fords own training manuals how a bottom ring picks up oil, lubricates the bore and scavenges the oil off the bore during the pistons travel.
Ford could not dispute it was in fact covered in oil to do its job therefore lubricated and approved payment.
I could not have done that on my own.

Get your ducks in a row and if you are in the right you may well be reimbursed, good luck mate.