CALL OF DUTY
Hey there, That sounds unfortunate. Are you using the console app or the ELITE website? Also, have you tried appointing another member in your clan as clan leader, then tried leaving? If this has not worked, you can always provide us with a link to your clan, your gamertag/SEN ID and the platform you are on and we'll look into the matter. You can reply here or reach us on Facebook https://www.facebook.com/ActivisionAssist , Twitter https://twitter.com/ATVIAssist or our Support website https://support.activision.com/ Thanks ^AH
Which browsers have you used when trying to leave the clan? Have you cleared out your browser's cache/cookies recently? Would it be possible to get in contact with the clan leader and find out if there are any inactive members or pending invites to the clan? Thank you, please keep us posted!