Bharatpe Merchant - Security Deposit Was Not Refunded even after returning the Swipe Machine

On October **, I met with Siddhant Jaiswal, Bharatpe Sales person in Rajarhat Kolkata to set up my Bharatpe merchant account with POS. I had paid Rs **** using phone pe to order the POS. He confirmed within * days, the POS (swipe machine) will be delivered. While ordering Siddhant clearly stated that Rs **** is a security deposit for the swipe machine, if I return the swipe machine anytime later this amount will be credited back to my account right away. There is no time frame in this process.
Along with this he had also changed the company account details to my private account to ensure the POS delivery as it did not allow him to process order with company account without GST from the Bharatpe portal.
He had also promised me digital POS but I received the keypad one. One asking be stated its an issue with his office.
While creating the merchant account he told me that he stated alternate contact details as ********** which is Konzept Techonologien Private Limited customer service number and told me in case my primary number ********** is unreachable then Bharatpe will try to contact me in alternate number.
After * days I called him and he did not receive until I caught hold of another sales agent Mr Biplab Das. He told me it should arrive within * days.
During the entire ordering process, no one not even customer service told me that the security deposit will be refunded only when the swipe machine is returned within * days of delivery.

The Swipe machine arrived on October ** and Siddhant visited one evening (after * days from delivery) to give us the demo of the machine and change the bank account from my personal to Private limited. He requested his senior to change it after getting all the details from me and left.
Now going forward, Bharatpe constantly tried calling me in our customer service number to confirm the change and even after that I called back in one number from which Bharatpe called and gave them my primary number which is **********. After multiple similar scenarios, I called Siddhant and he told me everything's being taken care of by his senior which never happend. He also told me that he would share his senior's number so I can directly provide him the details which never happened.
Finally I learned that Bharatpe customer service constantly called in my customer service number and whatever the conversation might be they stated customer agreed in their notes.
I was unable to catch hold of anyone neither the customer service nor the sales person so I had decided to return the machine back and filed a return on October **, ****. I also decided that I will issue a complaint against Bharatpe for the misguidance and reported the same to Siddhant. Right after that he started threatening me in whatsapp. He even mentioned that whatever I do there will be no refund for the amount which has been paid. In the same chat he stated there will be a refund previously.