Disabled phone and no computer
If it is not a temporary disable ( due to incorrect passcode attempts), and is permanent, there's nothing you can do except restoring it from a backup or resetting it. 

This help article clearly says that iTunes is required (either on a Mac or on a PC) to do so whether it is a friend's or apple store's.

The current data cannot be backed up but if you have a cloud backup, it can be used to restore it.