Can not add devices because "DevEUI already used"


I am using The Things Network and would like to use some GlobalSat LT-100.
But I can not add my devices by “DevEUI already used”.
Perhaps my colleague had added this devices.
Can I add these devices ?
DevEUIs are:

  • 000DB5320A8A3457
  • 000DB5320A7D343E
  • 000DB5311369354D
  • 000DB5311386356E
  • 000DB53113813553

Best regards.