Negative balance in demat acc

My broker using my POA executed trades and the brokerage company never informed me, now not only my initial investment of around Rs 50000 is gone but my account is showing a negative balance of more than 150,000 which comprise mainly of delayed payment charges, what happens if I choose not to pay the brokerage company to settle the account since they never informed me of this DPC in spite of repeated emails? I came to know of this only via SMS received from MCX and upon further inquiry from them.