Money not returned by relatives and they do not intend to return

We gave 1 lakh rupees to one of our relatives and they assured us they will return the money in December. On december they said they will return in Jan and same does on till April. On mid April we asked them to return the money as we are in urgent need. From last 15days they are giving different reasons like we gave cheque in bank. And after 2 days they said the money got refunded to them. They even shared a message thát money is debited and credited in our account ( I have never seen a debited and credited message in a single message and also how can money be refunded to them if they have message of credited). On checking the cheque reference number with the bank we found that The cheque was never submitted. For 1 week we followed up with them but they just said tommorrow which never came. Now we asked them to courier ( through india post) a post dated cheque. He sent us a courier slip with a courier company which doesn’t have any office in India except indore. The courier company doesn’t answer the call and switch off there phone. it seems they are scamming us and have no intent to give Money back. What should we do? Also will filing complaint we need to pay ?