Refund dispute with dollar thrifty.

I have laid a dispute regarding a refund against dollar thifty and they promised to refund me.I furnished them with the banking details,instead they paid into an account which is dormant.I recently sent them proof that the account which they used was no longer in use and now its been returned to them.The company is still not willing to assist and pay what is due to me.Please assist me by exposing their ********* business dealings.