Max Mag India - Not received my refund

I got selected for three advertisement shoots by Max Mag India, which is a casting company operating out of Mumbai. They reached out to me through the online talent recruiting platform Talentrack. I had paid them Rs. **** as initial risk deposit for the shoot. The shoots got indefinitely delayed due to the pandemic situation and I finally decided to back out of the project. It was clearly mentioned in the mail from Max that the candidate would be refunded the deposit if the candidate backs out after informing the company. I received a post dated cheque initially but received a mail from the company shortly after that mentioning that since some Indian companies are merging, the cheque is invalid and should not be encashed. It has been more than * month since the last communication and the company is unreachable now. They are still active on Facebook and planning an event with the Bollywood actress Urvashi Rautela in June. But they have stopped communicating with me. Their contact number has changed too. Kindly help me in getting my refund.
The company's Facebook Link is :
https://www.facebook.com/maxmagindia/