Idea Cellular — unable to port numbers

I have got two post paid Idea Numbers. Off late the network and data connectivity of Idea cellular has become worst at my location.. I have raised numerous complaints on email and to their customer care but nothing happen. I am noy able to port my number as it gives following error on porting reques.

UPC cannot be generated for the reasons: (1)There are subsisting contractual obligations with your service provider. Please contact your service provider for further assistance.

I don’t have any bill pending.

Kindly resolve my problem