Manufacturer service and maintenance intervals are maximum limit guidelines. Common sense should've been applied, and your cambelt should've been changed a long time ago. How can Citroen be expected to take any responsibility for the condition of a seven year old car? The manufacturer has no idea what the car has been used for in that time, where it's been used, in what climate, or anything. No-one knows what stresses the cambelt has been subjected to in that time.

It is your responsibility to know the condition of your car and what is required to maintain it, and if you don't know about cars then this does not absolve you. The advice would be to get clued up. Anyone who chooses to operate a complicated piece of machinery without knowing anything about it does so at their own risk.

Manufacturers warranties cover mechanical and electrical manufacturing defects. The failure of a cambelt after seven years service can hardly be described as such.

Depending on what engine you have, I assume its a diesel, some are designed for the rockers to break in the event of failure instead of damaging the valves which makes a much cheaper repair as the head doesn't have to come off. I know this is the case with the 8 valve 2.0. but I suspect yours is a 16 valve in which case I don't know.

This was certainly the case with 8 valve GM diesel engines too. Genuine rockers would break on impact, but those who suffered a cambelt failure after having fitted a non-genuine replacement camshaft and rockers were never so lucky, as non-genuine rockers wouldn't break.