Hi - we recently purchased OLAM theme for digital downloads - and cannot change the logo inspite of uploading fresh logo files. It still shows Olam.
I think you can change logo from theme options and/or Appearance => Customizer
After set your logo you have to save the changes.
Otherwise the best way to get the support is Contact your purchased theme Author. How to Contact Author and let them know. theme Author will be very happy to assist you.