Yes, employee must render performance according to the requirements of the job nevertheless, non-payment of the wages for which employee has rendered his/her services is against the law. That you did not get any output from that person is a different matter altogether. Therefore, the Area Manager was due to get his payment till his last working day.
By the way, this is a classic case of recruitment failure. Who were involved in the selection of the Area Manager who could not achieve even 1% of the target? Will your management conduct investigation on why they failed? In India employers are so obsessed with taking "experienced" person on board. Was the person selected had sufficient "experience' or not?
Lastly, you need to check your compensation policies also. How person of the stature of Area Manager can have salary of Rs 30K? For such paltry salary, obviously you will get candidates whose candidature was turned down everywhere.