In case of wallpaper damage, the affected area can be replaced with the same pattern. This requires a bit of care (to avoid ruining the surrounding area). It might be best to contact the Nilaya helpline or your retailer.
In the rare scenario of the wallpaper peeling, it can be set right with a suitable adhesive like Nilaya Premium Wall Covering Adhesive. However, if the peeling has been cause by wall damage, like a leakage or moisture problem, the wallpaper can only be re-fixed once the core issue has been resolved.