Could someone please enlighten me on how a warranty on workmanship operates.

About 5 months ago the gearbox of my vehicle crashed and I took it to an independent service centre to be repaired. My car's factory warranty had just expired, which is why I did not take it to the agents to be repaired.

The gearbox was overhauled and, while they had the opportunity, replaced the clutch assembly as well, as my car's mileage was about 160,000 km. I was given a warranty on workmanship of 6 months or 15,000 km, whichever came first.

Last week my gearbox crashed again (5 months and 10,000 km later), and I returned my car to the service centre, and they have repaired it at no charge due to the warranty. Apparently there was a fault with the clutch and pressure plate.

When I enquired as to whether I would be given a new 6 month/15,000 km warranty, they said that I only have the remainder of the original warranty and no more.

Is that the norm, or do I have a case to insist on a new full warranty?