Hi, I'm Pete. Welcome to JustAnswer! I'm reviewing your question now, and will post back with your reply ASAP.
The 8109 has nanoblades so it should give you a closer shave with less burn.
The batteries lose their effectiveness and need to be replaced after a few years.
If the battery is dead and will not hold a charge any more, then it will need to be replaced.
If you have installed a new battery and charged it, and the shaver still won't work, then the charging circuitry inside the shaver is suspect and it will require a repair or replacement.
Ok, customer services will take care of your cancellation.