Jio Fiber - Jio Fiber Trial Plan No Refund

I cancelled my Reliance Jio Fiber broadband connection on *th Oct ****. I received the message that Setup Box will be picked up within * days and refund will be processed. But still the box is not picked up and refund is not processed. Many time Jio Care have given the time to pick up the Box , but no one visited. Every day Jio Care give the new date. But still the issue is not solved.

They took my bank details and said that amount would be transferred within ** working days. They have not transferred the money back to me till now. They say that NEFT /IMPS was rejected but they do not give the details of the transaction. They have been asking me to give my bank account again for the *th time. It seems like they dont want to pay back and hold the amount with them as long as possible.