If you want to save this battery, I would try putting it in balance mode (not sure if your charger has this or not) and let the charger balance the 2 cell's voltage so they are the same. This might take a few hours depending on the charger. Once its done, do a balanced charge on the battery and see if the voltage is all over the place or not. If it is then pretty safe to say the battery is dead and not worth saving. See if there are any local electronic recycling shops or places that takes in lithium batteries locally near you.