Online travel agents has not refunded

You can give complaint through online. steps follows.

How to lodge a consumer complaint online

1. Website. The government runs a portal called the Consumer Online Resource and Empowerment Centre (core.nic.in). ...
2. Registration. To lodge a complaint, the consumer has to first register on the site. ...
3. Lodging a complaint. ...
4. Process. ...
5. Status. ...
6. Points to note.

As per your query!
A Consumer Court deals with cases regarding consumer complaints and grievances. The judiciary hearings are set up by the Government of India to protect consumer rights wherein unsatisfied consumers can file a case in consumer court against the seller on the grounds of harassment or deliverance of flawed goods or services. 

You may apply for District Consumer Disputes Redressal Forum (DCDRF): Established in each district, it comprises 3 members each. If the value of the claim is up to 20 lakhs then, an appeal may be filed from the order of DCDRF in the State Consumer Disputes Redressal Commission.

I have laid down the link below for your convenience

https://www.onlinelegalindia.com/services/consumer-complaint/?utm_source=GoogleAds&utm_content=OLI_ConsumerComplaint&gclid=Cj0KCQiAy4eNBhCaARIsAFDVtI3V2RGdvkx0CFLblb4YyMQbjai70H0cQUUhvWdbvDU7cuh8o0TW_-AaAo5sEALw_wcB#2&Campaignid=14599378723&Adgroupid=129781976529&device=m&Adposition=&physical=9301993&match_type=b&network=%2Bhow%20%2Bfile%20%2Bcomplaint%20%2Bconsumer%20%2Bcourt&target_name=aud-973723604140:kwd-1009572544044&placement=&keyword_id=%2Bhow%20%2Bfile%20%2Bcomplaint%20%2Bconsumer%20%2Bcourt

Hope it is useful!
Regards
Minakshi Bindhani