Turtlemint — Deactivation Request for POSP code

I am exhausted now, I am trying to deactivate my POSP code since 6 months back in company and in the ENVOY self deactivation Portal. In the ENVOY portal an error is showing "Your Deactivation Request has been declined" and the Company has not responded. Please tell me what can I do next.
POSP code: DP-4014212

Please help