Quite!

The manufacturer in question is currently holding their line that it's perfectly normal for them to fail after such little use. I've spoken to an expert in the field and have been told that some do fail but usually they last many tens of thousands miles and many years.

I'm waiting to hear back from the manufacturer (they're currently insisting that I buy a new one, but that wouldn't be ready for some weeks), if they fail to satisfy though I shall name and shame. Because their work has been so good in the past I'm hoping that it won't come to that.