This is clearly to me a problem that should have been sorted whilst still under warranty. The fact that it wasn't, and is getting worst ( you are now getting minor shocks ) to me would be a worry.
The problem could be either the charger or the laptop, These require checking by a fully qualified Computer expert. And their report retained.
You should inform the makers who will be aware of any issues .
Hopefully you have made a backup of all your personal data
My advise would be NOT to use or CONNECT TO THE MAINS until an expert declares it safe to do so