I have experience of Kef's service dept. and can say that I was treated more than fairly and very quickly indeed.
Having purchased a second-hand TDM-45B from Ebay with what I thought had some time remaining on the warranty, I was not particularly worried when the amplifier section soon developed a fault.
I spoke to Kef support who recommended I removed the amplifier myself and send it back to them for repair. A few days later I got a call to tell me their 5 year warranty only applies to speaker drivers and not electronics! I was not amused by this and asked them to let me know what the cost would be before repairing the unit. The next day an engineer phoned to say they couldn't isolate the problem so they would just send a brand-new replacement amp out to me.

These things ain't cheap (300 watt, THX)
And all this took about a week. Don't worry Kef have excellent customer service.
SMP