Bharat Sanchar Nigam [BSNL] — Not allowing me to port out of BSNL.

I purchased the BSNL sim to get 4g services but didn't get it, so wanted to port out of BSNL.
But everytime I request for UPC code I get the following message:
UPC cannot be generated as there are subsisting contractual obligations with your service provider. Please contact your service provider for further assistance.

BSNL is deliberately not allowing me to port out to make me continue using its worst services.

I've seen several other similar complaints regarding BSNL which means the company is deliberately cheating it's customers.

Please help me resolve the issue as soon as possible.