We want to change our old CA but he is not giving NOC

Dear Members ,

Ref. to the subject , this is to inform you that I am working as a Head Operation in a HR Consulting Firm . We want to change our Old Chartered Accountant and we have already discussed with a new CA to whom we know personally .

But to start the work he( the New CA ) needs NOC from the Old Charterd Accountant .

But the Old CA is not issuing the NOC after a several request from our side. We have discussed with him , sent him mail , sent him request letter by courier also . But neither he is responding nor he is issuing .

Please advice . Its Urgent .

Thanks & Regards

B M Dash