Hathway Broadband Internet - Threatening calls from the company

I had taken a Hathway connection in March **** when I was in Bangalore. The executive suggested me that if I opt for * months subscription l get modem free with the connection. I need not to pay for it. So I opted that and used it for * months then I moved out of Bangalore. Initially, I got calls for recharging my plan as I was not using. I said that I don't need it now. I'll recharge it when I feel like as my mobile data was not enough for me. When they started calling every second day I said that I moved out and can not use it here. So they asked me to return the modem. First of all, if I would not have told them that I moved out, would they have asked me to return it or asked only for reactivating my plan. I told them that I cannot come back to Bangalore to return it now. If they can arrange for its pickup, I am absolutely fine with it as I was not using it at all. To avoid those daily calls I agreed to return. They said okay sir we will check. Now suddenly after * years, I got a call from a lady stating that she is from consumer court Delhi and a case has been filed against me for not returning the modem. I don't know whether its a real call or some fake call. Secondly, how can someone expect me to return things which I was never told about to return? It was told free. And also how is it possible to return when i m not in that city. Who carry a item till * years which is of no use to him/her.