Some battery packs may just need some balancing to restore the initial performance.
Your BMS can be replaced with a new one, for instance - SMART BMS. Price may vary on a battery pack size and complexity and does not include the cost of the BMS plate.
Price may vary on a battery pack size and complexity and does not include the cost of the Li-Ion cells.
Some battery packs may have insulation damages, this should be fixed with a new heat shrink and adhesive.