i'm in the process of dealing with the same issue with nissan GB. was last told that i was not a loyal customer so they wouldn't do the work. so i wrote them a letter, that was 3 weeks ago, rang them today, and apparently they sent my reply just before the bank holiday. so hopefully have their latest reply tomorrow.
if its not what i want to hear i'm back on the phone. nissan are going to fix my problem, they just don't realise it yet.
its a nissan fault, i didn't cause it through wear and tear, its due to an issue at the factory, its a noted problem, its theirs to pay for and fix. and thats the line i'm taking, and no is not a reasonable answer.