Attorney demanding payment without written contract or verbal agreement.

An attorney is entitle to bill a former client for the time spent working on the client's case.  While written fee agreements are required in injury cases and while written fee agreements are recommended for all cases, not all attorneys follow these best practices. If you had a prior relationship with the attorney, then the prior relationship could constitute an understanding as to fees, Your former attorney appears to be asserting a quantum meruit claim for fees. Contact your local bar association.  Most local bar associations will assist with fee dispute issues.  Just getting a letter from the bar association regarding the fee issue might be enough for your former attorney to back off his claim for fees.