Air India - Air India Cheating Customers by not Providing Refund

I had booked roundtrip tickets on Make My Trip for my parents on February **, **** as my parents had medical appointments. The Kolkata to Chennai tickets were booked for April **, **** and the Chennai to Kolkata return tickets were for April **, ****. Air India changed the trip dates to April ** and April ** respectively without any warning. Since the doctor appointments were fixed for April **, I had to cancel the tickets. Before cancelling I had contacted Air India and one of their agents informed me that I will receive full refund since it is Air India which had rescheduled the booking and that the refund will be processed within ** days. I had approached Make My Trip with this information from Air India and they sent a refund application for the tickets to Air India on March **, ****. But despite several calls to Air India, and sending continuous mail to them on escalation.web@airindia.in, they have not done anything to process the refund. When I ask their agents regarding the status of the refund, they keep saying that Make My Trip needs to send a Refund Application, which as mentioned before was sent way back in March **, ****. They have not bothered to respond to my mails and it has been nearly four months.
This is not expected from a government owned enterprise that too one that carries this nation's name. Air India has provided no help whatsoever, their agents are rude and unprofessional, and finally they don't even bother to respond to customer mails.
Government must take serious action against such negligence and see to that Air India provides timely refund to customer, particularly when they decide to change flight schedule even without consulting the customer.