If the battery of your battery-operated device is defective and we cannot offer you a replacement battery, there is still a way to replace your battery.
Option 1: If it is a commercially available battery, you can buy a new one on the market.
Option 2: There are specialized service providers where you can send in your battery and have it repaired. (Example: https://www.akkushop.de/de/themenwelten/akkureparatur/ ). You can find these online or possibly in your local shop.