If the screen is locked with an unknown PIN, password or pattern, there is no way to reset the phone without erasing all user data.
Since the device lock will prevent you from resetting via the Android settings, a reset must be done with a hard reset from recovery mode. For detailed instructions on how to do this, see the document on reset options, in the section titled Hardware reset to factory defaults.
If the device has also been configured with a Google account, then resetting the phone will not help, due to the Android Factory Reset Protection mechanism. In this case, you will not be able to proceed through the Setup Wizard after resetting, without providing the Google account login. If you also don't know the Google credentials, then the device can only be reset by BARTEC. In this case, please contact us.
Devices that require repair or service must be processed through the RMA procedure.
https://bartec.com/service-support/returns-repair/
Please use the procedure for "Automation and enterprise mobility"
Fill out the form electronically
Send the form to services@bartec.com
Once you have received the RMA number, you can send the device to BARTEC along with the printed form.
Shipping address:
BARTEC GmbH
Service center
Max-Eyth Straße 16
97980 Bad Mergentheim
Germany