Zoomcar — The refund amount is not yet credited to my account.

I had used zoom car service on 17th may, as a part of their company policies they have taken 3455 as advance amount. We returned the car and the journey cost was 456 but the advance amount is not refunded yet. I have tried to call them many times, 2-3 times they attended the call and said they will return it with in 30 working days. I called them after 30 days no response from their side and they are not even attending the call.