I can understand you're dissatisfied, but one mistake on a non-pro camera wouldn't cause me to '"won't be buying from them again".
The problem is it isn't just
one mistake. Sony have a terrible reputation for service in the UK.
I know several people who have suffered at the hands of their 'service' departments.
In my own case I took a £1000 (in 2001) video camera in for a warranty repair, it came back with the same fault, on the second attempt I told them that I would collect the camera in person to check the repair, but they sent it back in a cardboard box with NO packing.
Then there was the Viao laptop that took four months to fix.
Sony make great kit, when it works, but their after sales service is just appalling.
The one part of Sony in Europe that have acceptable after sales service is their broadcast division, but it's a worry that one company I know brought four new camcorders and have had to send three of them back for repair within the first three months.