I used to have a client who pays me $3000 every year to maintain her small office's computer, network, email and static website. There was no written agreement for this since she was recommended to me by a mutual friend. The payment was usually credited to my account towards end of the year or first week of the year.
About a year ago, I tried calling her to remind her of the pending payment. She ignored my call, email and Whatsapp message. There was no formal written or verbal from her stating that she no longer require any of my service. I stopped contacting her since and neither did I render any service. She of course, did not contact me as well.
Today she texted me via mobile asking for password to a certain application. How do I remind her outstanding payment that was due a year ago without sounding like I am extorting her for it. I still have in possession, passwords, media and documentation which I intend to handover to her once she release the outstanding payment.