Excitel — Not refunded the Security amount

Hi,
I have taken a WIFI connection for Excitel and used it for some time. Because of the service issue by the local provider I have canceled my connection & returned the modem in Feb 2021 to the provider when I have asked him to refund the security, he told me to wait for another 2 months as security will be returned by the company. After 2-3 months when I have chased them for the refund they continously denied for the refund. Now it's almost 9 months I am cahsing for the refund but thay are denying it by saying that they are still waiting for the refund from the company.
I have the slip with me for the refund from SUNNY BROAD BAND but they are not refunding the amount.

I am very disappointed with your provider & the services provided by excitel.

My connection was with the name of Amit Chawla, contact number- [protected], Address- B 11, 2nd Floor, Mahatma Gandhi Road, Adarsh Nagar, Delhi 110033