Refund not given by travel agency when already informed to cancel trip

Dear Sir, I have booked holiday package for Rameshwaram on 19th Apr'18 by paying Rs 20,000 but due to some reason cancelled the booking on 21st Apr'18. ( Travel dates is 9th June 2018) Request mail sent and information given on customer care. After discussing with customer care person again final mail sent for cancellation. They informed me that process will be initiated in 3-4 days as per company policy. But from then many follow up , calls & emails , no respons received from  team regarding my refund. Not even any acknowledgment given for processing. On 4th May again i have written mail & call but still they said we process not started. Then i have mailed on 16th may to all top officials for my refund . then they called me & told that ur refund process not initiated and you have to travel on these dates only as package is confirmed ( because of their mistake only they have not cancelled).still they are not giving any refund and confirmation. I am need you expert advise