Good afternoon, all.
I've had this problem as well; the battery failed on my 2008 1.9JTDM in 2012 (after 42,000 miles) in a hotel car park 250 miles from home. It was the original fitment and was, I think, a Varta. I suspect that, with the very high starting load, these batteries have a limited life - in contrast the battery in my 11 year old VW Polo 1.2 is also the original and shows no sign of failure.
The RAC turned out, got the car started and pointed me in the direction of Kwikfit in Poole. I'm not a fan of Kwikfit, but on a Sunday I had no choice and they were able to supply and fit the correct size battery which has worked well since.