Keep getting annual charge for microsoft hotmail/outlook and don’t know what for

For the past few years I have been charged an annual fee of $37.95.  The description for the fee on all my accounts is "Microsoft Hotmail North Ryde Aus" and since this year "Microsoft Outlook".  I have no idea what these charges are for or how to cancel them.  I have looked around on my hotmail/outlook account and found no indication of any subscription fee or of how to cancel any such fee.