Due to the disposable element of the cartridges, they come without warranty.

Filling Instructions:

This is the easiest way to fill up cartos, using the rubber cap that comes with them.
Here's a vid - don't forget to wipe off any excess liquid, especially at the battery end -



And here is the technique again, more in depth & detailed -



And here's another way (but it's more hassle) -

Remove the 2 plastic covers from the cartridge. Remove the plastic cap from the bottom of the carto followed by the round silicone insert, using a pointed implement. Leave the thin plastic storage plug in the hole in the battery end of the carto, while refilling (also make sure that the battery is not connected to the carto, because you do not want excess liquid to drip into the battery). Add about 18 (no more than 20) drops of e-liquid into the wadding until fully damp. Make sure the liquid is evenly dispersed in the wadding. Pop back in the silicone insert followed by the plastic cap.
Leave to settle for a few minutes before use.

So this is the more traditional method showing how to refill a KR808D-1 cartomiser (Vapor King), the same type as the Creator cartridges -