When we bought our new home (Taylor Wimpey), they were very clear that they would do repairs, but only to how the finished house was when we took ownership.
If we painted a wall red, they would cover the repair with their standard white. If I tiled a bathroom, they would not replace tiles if they had to remove to repair.
Likely, as you said you privately had work done on your carpets, it is not covered anymore to the standard you are expecting.