Axis Bank charging processing fees even if credit is not given

Location/place: India

Name of company/service: Hypro Engineers

Axis bank had given a sanction for credit limits so we paid them processing fees. Later they cancelled the facility however did not refund complete fees and retained 50,000 rs for no reason. After a follow up for a year now they state they wont refund rs 50,000.All documents and corresepondence is available with us. They have tried to cheat us,